Found a couple soda pop can, pull tabs in an old car at a friends house. Brought back a few memories.
They were a liter problem. Pull tabs got discarded in cars, on the street, you’d find them scattered on tables at restaurants, I even secretly dropped a few in my dates purse one time. 
Is that why they developed the newer openers that stay attached to the can? Whatever the hell they call those things. 
They were a litter problem but they also hurt people who would (stupidly) drop them into the can and then choke on them, or drop the on the ground to get stepped on. The sharp edges ehre just asking for trouble. Also they were generally more difficult to open than pop-tops are.
They made the new ones because of the litter problem that you mentioned. Some states banned them earlier than others, so in some areas the pull tabs disappeared back in the early 70s. In other areas they remained well into the 80s.
I’ve always called the new ones pop tops. I have no idea if that’s the correct name for them or not. There were other systems tried that did not work as well. I remember some cans having these raised circles that you had to push in with your finger. Not only was it harder to do than a pop top, but you could also scrape your finger on the sharp edge of the can if you didn’t push in the middle.
ETA: Skammer is right. Safety (choking hazard) was also often given as a reason for the change.
Sometimes the tab would break off and you had a jagged sharp piece of metal sticking up from the can.
I blew out my flip flop
stepped on a pop top
cut my heel right down to the bone
Old pull tabs and the newer pop top tabs have also given birth to the Urban Legend that dialysis patients can redeem the tabs for money/dialysis time.
~VOW
The changed so that the people of the post-apocalyptic Chicago-area would have a form of currency.
I never knew what that last line was!
Gee, life must’ve been really cheap in the olden days.
My mom reminded me that kids used to put the pull tab rings in coke machines. They were trying to use them as fake quarters. It was a PITA because it would jam the coin mech. I recall at Scout Camp some idiots did that. 95 degree June weather and we’re all dying for a cold soda and the machines were broke. It took a couple days for the guy to come out and service them.
I believe they used them for smaller containers as well. 
Also, I thought the line from Margaritaville was “cut my heel, had to cruise on back home.”
Beaches were a rough place for a child in the 70’s. It is amazing any of us survived the experience. They always told us those things would last 500 years or more even after we stopped making them but I don’t see many around even when digging. Where did they all go? For that matter, where did all that crap from back then go? I don’t see much plastic from the 60’s laying beside the road or even in the woods.
That, however, wasn’t it.
The line is “Cut my heel had to cruise on back home.” The other version was probably a joke, but it clearly doesn’t fit the rhythm of the song.
National Kidney Foundation (NKF) Dispels Pull Tabs For Dialysis Time Rumor
New York, New York
Monday, June 1, 1998
*“A false rumor that has plagued the National Kidney Foundation (NKF) and the aluminum industry for decades has recently resurfaced, perhaps fueled by the Internet.
Individuals and groups believe they can donate the pull tabs on aluminum cans in exchange for time on a kidney dialysis machine. …”*
http://www.kidney.org/news/newsroom/newsitemArchive.cfm?id=100
If anyone wants to discuss the monetary value of pull tabs or charities that collect pull tabs, there is an ongoing thread here.
I recall it also meant your bartender was often sticking his fingers into your beer. 
I knida remeber kids collecting those things and making long chains out of 'em sort of how the previous generation made chains outta chewing gum wrappers.
Also IIRC, the pull tab was 17% of the aluminum in the can. With it being detached a lot was being lost for recycling purposes.
(Wiki is down so I can say whatever I want.)
Aluminum is the most efficient product for recycling. 17% is significant in the big picture. A better method was very practical.
I’ve seen old cans and pull tabs in abandoned buildings
Didn’t the Straight Dope once answer a question about why pull tabs were still common on meal replacement drink cans, V8 cans, and the like, decades after they disappeared from pop/soda/beer cans?
The ones I’ve seen recently aren’t the same kind of pull tabs. The new ones aren’t metal at all, they are a sticky tape (maybe aluminized) over a pre-cut triangular hoe in the can. Those aren’t as airtight and won’t keep the product fresh for as long as real metal covers, but that doesn’t matter, since they are mostly used on products with a faster expiration date than soda pop.