Yes, I'll acknowledge that there may be a handful of capable researchers who are able to progress on some basic science by accepting free money from a scam industry which is indiscriminately shoveling it at anything that might appear to legitimize itself.

Just as, in days of old, those who wished to do legitimate (and costly) science had frame their research as supporting alchemical beliefs leading to discovery of immortality, or means to make gold from lead.

and astronomers who wished to build an observatory had to go along with some highly flimsy justification about how it could serve as a means to prognosticate the birth of an heir or victory in battle for some petty murderous strongman.

How much do these ideas depend upon the concept of blockchain?

They don't depend on the blockchain, but the fact is that most recent research on these topics has come from the blockchain/cryptocurrency space.

One interpretation is that crypto companies need security and privacy, while big tech doesn't seem to care all that much.

uh... so you're saying hypothetical coinbase cares more about security than hypothetical robinhood or fidelity, or even the good ol' google/apple?

(i'm having a hard time thinking of a successful "crypto" company other than a handful of exchanges, of which coinbase will probably be the only one that survives, at least in the US)

I don’t know if “cares about” is the right phrasing, but financial transactions are a “simple” use case for ZK algorithms. So practicality if implementation definitely affects how much a group or company cares.