I also think there are real grey areas too. Some #coins like #filecoin and #orchid are theoretically useful. In those cases you need to be able to see that there are better alternatives to blockchain to fulfil those uses.

That's not really a trick in either case because it's quite possible the authors really believe in what they're doing. We have no way to tell.

Other examples like #qrl are actually half persuading me they're necessary, since e probably will need a #quantum resistant ledger at some point and even at worst QRL gives that problem attention.