Why is a letter about crypto referring to Fintech in general in the title? To me this shows a distinct lack of context and the view that these people think they know a lot about crypto, but know very little about finance and moreover the authors don't think they need to know much about finance. For example, the bald assertion that crypto has no real world use cases ignores the work happening within traditional finance to use blockchain for trade settlement.

Do I know everything about these topic? No, but I'm not writing a public letter soliciting signatures.

Am I a crypto shill? No, I think current crypto is a rip off, but this letter isn't a good argument for that. It's too light on details and doesn't acknowledge the areas where it could be valuable.