No, probably because it’s false. Just the calculations you cite here are more complex than a decimal transation and require more facts to be memorized to employ.
In a theoretical world where any human used a base-12 numbering system, as Sunspace theorizes, a base 12 monetary system would have a few more advantages vis-a-vis being more easily divided. But we’re using base 10, and base 10 measuring systems work best.
Keep in mind that we Americans have the most boring money in the world. We basically have four coins and four bills. And up until very recently they had remained unchanged for decades. Any attempts to make changes to our basic money system is usually extremely unpopular and heavily resisted.
I get looks and sometimes a hard time when I try to use either a Sacajewea or a Susan B Antony coin to buy stuff. Those (and the Kennedy half dollar) would be the only “rare” coins seen over here.
I am also surprised that UK’s system wasn’t unified when the decimal change was made.
Well, kind of. Along both borders of the USA, they freely accept US currency in Canada and Mexico- especially down south. Not so much the other way.
But a 2# coin? That’s like a $3.50 coin? Pretty unweildy?
As a slight aside, it used to be that in Northern Ireland (and possibly the rest of the UK) each branch of each bank could issue notes of its own. My Dad retired from the Ulster Bank a few years ago, he had a little display made up in his branch with one such note included as the history of the branch when he worked there.
Why? If it’s still nowadays not a big problem to have different banknotes, why should it have been an important issue then?
All this talk about “Scottish” banknotes is a bit misleading. You actually have banknotes from the Bank of Scotland, the Royal Bank of Scotland, the Clydesdale Bank, and…what, one other one? They all come in the same denominations, and each denomination is generally the same color across all the issuing banks. (I forget if they follow the Bank of England color scheme.)
Even as a foreigner*, it wasn’t confusing, though. I mean, they all have the number printed on them and come, like I said, in standard colors. Less confusing, really, than the different styles of bills in circulation right now in the US. They also have lots of hard-to-forge official looking things like watermarks and microprinting, too, if that’s what you’re concerned about.
*[sub]Well, not really. I mean, I was born there.[/sub]
The Scottish notes are well behind with regards to security issues
So are US notes, but they still manage to have watermarks and microprinting. My only reason for mentioning them is that the OP is concerned about the confusion caused by having lots of different notes. It occured to me that this could cause two types of confusion. One is “What value of money is this?” The fact that money occurs in standard denominations of uniform value and is color coded and clearly marked pretty much eliminates this. The other type of confusion is “Is this money at all?” Watermarks and microprinting won’t eliminate the most sophisticated couterfitters (little will), but they do a perfectly good job of allowing a shopkeeper to distinguish an unfamiliar banknote from, say, Monopoly money, a novelty 3-dollar bill, or a newspaper coupon.
Trust me i yearn for the money of my homeland. All the damn notes here are the same size and the same colour - how on earth is that easy? I love being back in the UK as it means i can tell at a glance roughly how much money i have without having to stop and count it.
I still haven’t worked out why there’s a picture of Peter O’Toole on the twenty dollar note yet either 
For no good reason other than I like things tidy, dammit.
I’ve come across this concern here before. People who are used to having a wallet full of dollar bills think that having a handful of coins instead must be annoying, while we find the opposite to be the case, and prefer to have some loose change rather than fumble with near-worthless paper. It’s just down to familiarity. (And btw, it’s ‘£2’, never ‘2#’ 
)
I suppose you’re right that it can be more difficult to check multiple notes for counterfeits. However, because the Scottish and N Irish notes are produced in much smaller quantities than English ones, they’re far less attractive to counterfeiters.
It’s not that they take pleasure in giving Scottish money in change; Scottish money is 95% of the money you see here (and I live only fifty miles from the border.) The English £5 note is quite common- there seems to be a bit of a shortage of Scottish ones, but you very rarely see a £10 or £20 note.
Going back to England, the money looks quantly pastel compared with the solid and dour greens and blues of Scottish money.
There is one Cash machine in our local town which dispenses English notes!
I have only rarely had any problem with using Scottish notes in England- sometimes the cashier will refer to the manager.
And the small scale production of Scottish notes makes large scale forging unlikely- you would have to spend them in Scotland as any unusual note increases the observation thereof and would make changing forged notes even more dangerous.
It was rumored a few months ago that Scottish banks may be forced to give up printing their own notes. English banks pay the Bank of England for the use of Banknotes printed by them. Scottish banks are required to lodge a percentage of the total issue of their notes in Sterling deposits with the Bank of England. Gordon Brown was talking about regularizing this (as it is a bit of a subsidy for the Scottish banks) and the banks started threatening people with English notes- made a good story for a few days.
I’m actually bored with the £1 note, as that amount of money is better to be in a coin format these days. We keep it mainly to be different. However, if I get one, I try to make sure to scrunch it up in a pocket or purse with coin change, in order to avoid the nasty sruprise of checking what notes I have, and finding that one of them is only a £1 - rather a pain when I expect it to be £5 at least. 
Oh, and there are some idiotic things like machines that require one pound, and OF COURSE, it is one’s bad luck to encounter them on the very day that one has no pound coin, but does have a pound note. Nah, to be fair, that’s no real hassle - such things usually just involve a quick swapping of money with a passer-by, just as when one has the pound, but not all in the one coin.
I am still not used to the £2 coins,though. It’s nice, when plucking up courage to see what money I have, to find that one of the pound coins is actually a nice big surprise whole TWO pounds, but for soem reason, I have a habit of getting rid of them at the earliest opportunity.
I recall my brother’s friend, a student from Nigeria, who was mightily surprised at a Scottish (Clydesdale Bank, I think) £10 note, because of a little map of a bit of Nigeria on the reverse, (the connection being Mary Slessor). He was very fond of those note - me, I am not fussy, I just wish I had more of any of them.
I always wondered what that map was!
The smaller Australian silver coins (5c, 10c, and 20c) can be used in New Zealand and vice versa- they’re the same size and shape, and so are generally accepted to be freely exchangeable. The 50c pieces of each country are different shapes (NZ’s is round, Australia’s is a geometric many-sided shape whose name escapes me at this point), and our respective $1 and $2 coins are different sizes too… in Australia, the $1 is big and the $2 coin is small, whereas in NZ it’s the other way around. I’m inclined to say the Kiwis got it right on that one, unfortunately.
Interestingly, vending machines and parking meters in Australia will take NZ 5c, 10c, and 20c pieces, which means if you want to be ultra-stingy, you can get a 10% discount on cans of Coke or on-street parking by paying with NZ coins.
Of course, actually finding enough NZ coins to use in the first place is a bit difficult without going to New Zealand (an activity best avoided, unless you’ve never seen mountains or sheep before 
), but it’s an interesting-but-utterly-useless fact you can bring up at parties to enliven otherwise dull conversations…
That reminds me of when the U.K. had PROPER sized (i.e.old ) shilling/5p coins. It happened that machines that wanted those would also take Deutschemarks - a very useless fact because a Dmark was worth more than a 5pence/shilling, but what the hell …
He was great in “Lawrence of Arabia,” and the printer was a big David Lean fan.
It’s only a few years since they disappeared, but I’m not sure if I’m imagining this - anybody like to confirm or deny that Irish 50p coins were the same shape as British ones?