> Why are you assuming that just because something doesn't involve money, people wouldn't be interested in it?

Because random hashes are not inherently interesting to most people and the core concept is built around an opinionated finance model. The only value to the blockchain network is in the ability to make transactions, and that's why all of the push around it is very heavy-handed FOMO “buy now or you'll have to pay more later” which is a sharp contrast to previous new technologies which focused on what new things you could do.

I'm sure that some people would continue to run crypto nodes if it was not profitable, but the number of people doing so would drop precipitously. There's a huge portion of the crypto community (90%? 95%?) that are in it for the ROI and speculative gambling, not for running a decentralized web.

As an example, I suspect no one would buy old power plants and turn them into Bitcoin miners if there was no return on investment. The operating costs of this kind of infrastructure are too high to justify as a "hobby".

But cryptocurrency has no value or meaning if it's not worth money.

That's not true of those other things.