> Both these goals seem to have failed in practice, the latter spectacularly
That will stop being the case once people stop treating all the coins as investment speculations. That won't occur until the bubble pops. After that, with the typical trauma that goes with it due to financial losses, it will become almost impossible to convince people to plow large amounts of money into inflating a given coin (as in the case of so many of the lesser crypto-coins that are seeing musical chair speculation booms).
The speculation on a stray coin to moonshot next, is no different than the speculation on which beanie baby will soar next circa 1998/99. Once the bubble gave way, you could no longer convince anyone that they all should be worth large sums, or that the musical chairs of inflating one beanie baby to the next should continue. It's classic group hysteria and it tends to reverse violently.
Once that occurs, you'll find the exact opposite problem more common: nobody will want to bother wasting any money on nearly any coins, in any regard (whether for transactions or sheer speculation). Group think will shift to nearly all coins as being worthless, as they actually are.