Taking any one scenario where it didn't work out that way is highly selective cherry picking. There is not functional equivalence between "almost always impossible" and "almost always possible".

For the actual topic, I don't have any respect for these ICOs/mints/[newest renaming], they're shameless cash grabs with 98% marketing and 2% upwork-tier code. However, you can burn a million quid; I don't think it's a big deal that you can burn 34 million in digital currency due to extreme negligence.

That's fair, I just see lots of discussions where single examples are used to (often literally) say "that's no different from other finance".

And I agree reversibility can be built for crypto, it's just that right now that is not the norm, and defi probably won't see wide adoption until that changes a bit.

KLF much?

Elaboration: https://news.ycombinator.com/item?id=31139114

And of that hack, I think something like 90% of the transactions for stolen money were reversed, but a significant portion got through because of the timing.

edit- and IIRC the whole thing was caught because of a typo?

A better summary might be "transactions are reversible in more cases than you would expect."

Also, transactions that aren't reversible at a low level are often reversible at a higher level in the stack.