Fools.
Maybe...maybe not.
Every retirement portfolio should have some modest allocation to high expected return but high risk assets. Crypto certainly fits that bill.
If they over-index that allocation then if could be deemed foolish.
I am hardly a crypto guy - there are plenty of operational risks that haven't been fully tested yet - but clearly there is something more to this than the usual, generational shift. Purveyors of crypto chat it up as a rejection of traditional assets, and in some ways a rejection of state/crony capitalism.
If that's true, then perhaps the fools aren't them.