I never understood the objections to the $1 coin, especially after the redesign to make it more distinct from a quarter. $1 coins are great for buying stuff out of vending machines since you don't have to fight with a dodgy bill acceptor or a mangled bill.
It’s because retailers wont accept them - they think they’re counterfeit because no one uses them. A catch-22 situation, really.
But I've never found a retailer willing to give a $2 bill as change.
The resistance to the $2 bill is a very weird cultural thing.
Mostly retailers don't stock $2 bills (because they're weird), so if a customer brings a $2, the cashier will put it in their their exceptional bills area, which usually is just large bills. No change is made with exceptional bills, so twos don't get recirculated.