One of the not so serious ones.

Most people understand that attempting to buy a single stick of gum at 7-11 with a $100.00 bill will incur some delay while the metered change machine disgorges ten and twenty spots at a slow rate. Accordingly, most people desiring a speedy transaction will ensure they make change before making the tiny purchase at 7-11.

Personally, having a wallet that contains only a single address (actually unspent output) seems rather astonishing to me. Accordingly, I never really thought about this problem before. Yes, it is a problem. But I don't see it as a problem with the protocol. I see it as a user problem. The user could have made change before going to the bar. Further, if this becomes a recurring problem, I imagine the wallets that reach success in the marketplace will ensure that the funds therein are always balanced across multiple unspent outputs.

So, no. I don't agree with you that this is a serious problem that dooms bitcoin to obscurity for all time.