because what they can offer isn't valued by capital

People categorize people as 'useful' and 'useless'. Hell, get down to Biology 101 and mate selection, animals select useful against useless. What do you have to offer?

"I'm having a heart attack! Help!"

"I'm a really nice guy that does wonderful paintings of the local pelicans!"

"Fuck off, I need a skilled physician and I'll pay anything right now!"

Yes, people get paid more or less dependent upon their use to society. Why would society support you if you have little, or nothing, to contribute? For those of us in first world countries, we're populous enough and technologically advanced enough to support a wide range of talents. Of course there are plenty of counter examples, but that's mainly how it goes in any given economic or governmental framework.

tl;dr: We're social animals with needs. Fulfill needs or GTFO. You don't have to like it, but you better understand it.