I try to buy as much as possible with cash, partly for the specific reason that I want change. If my total is $9.07, I don’t hand the cashier a ten and a dime, or some such thing; I maker her give me the 93¢ in coins. I do this because it “cuts” every dollar I spend, and serves as a small brake on my total spending. When I gather enough coins up–it usually takes about 3 months to gather about $75–I roll the coins up and take them to the bank to “paperize” my money.
Nowhere in this process do I find it to be burdensome; even the rolling of the coins is OK with me, because I enjoy lingering over that pile of clinky cash, so I don’t worry about the value of my time–it’s a kind of recreation. And I’ve never had a bank hassle me about changing the coins for bills. (I usually go to a branch of my own bank, which may help, but I’m never asked if I’m an account holder or not.) I know about those Coinstar machines, but I never use them, because a) they’re usually out of order, and b) I know there will be a surcharge, and I’m not enough of a sucker to pay the surcharge.
So I don’t see any problem with gathering up coins. In fact, I find it fun and useful. If you don’t like your coins, send them to me.
As for Heinlein, I’m not expert enough to comment on his love for “hard” currency, but I also remember that–in his stories at least–the old man wasn’t exactly down on gambling (back before there was an indian casino on everyone’s front lawn), or everyone walking around naked and humping like crazy, or even incest (assuming there were no bad genes in the mix). He had his quirks, and the currency thing was just another one of those, it seems.
What would be more interesting to me was how Heinlein would have felt about the seeming move towards the elimination of money altogether. This thread touches on that, at least in terms of the attitude of the commercial makers. I can’t imagine RAH being cool with paying for everything with a piece of plastic, and thereby leaving a paper trail of where you’ve been and what you’re buying everywhere you go. Being tracked like that seems antithetical to his ideas of freedom (mine, too, for that matter). Given that choice, I think he’d accept paper money over credit transactions, whether the specie was backed by gold or not.