>Assuming they are not doing it for revenue, where their income depends on huge readership, why are they so concerned with how many readers they are getting?

Are you including indirect revenue in your assumption? There's lots of hopeful incentives that don't immedialy lead to money:

- you get a reputation and get professional gigs or invitations or whatnot. Fame, in a word.

- You get a reputation and that makes it easier to validate your next pitch for some dream idea you have. For better or worse, saying "a lot of people like this" is very effective pitch material.

- you want to meet other like minded people and organically network. These can lead to future opportunities you would have never considered.

- You have some larger societal mission, and that requires society. If you have some altruistic goal of say, teaching everyone to code (to pick a cliche idea), then you need people to participate to realize your goal. Something like Khan Academy still needs to advertise itself.

Your view only really applies to people who want to do Art for themselves. But we are still a social species, we have a natural urge to share our creations, for profit or not.

One of the things is wanting to be part of the discourse. For instance, this has happened to me several times - big players are talking about a particular topic. I dig through the primary sources, and see that many of the assumptions people are making about it are wrong. I try to bring it up, but - where? Blog/Tweet about it, and with no audience you're yelling into the void. Sometimes I try contacting the big players, but like I said, it's a pretty cliquish environment, and if you're a nobody you get ignored. Another option is to spit out a lot of garbage dopamine hits to build up a big enough audience to the point where someone might pay attention to your good points.

In the end I just gave up, because I realized the state of discourse in these spaces is terrible. It's a shame, though, because there are a lot of small, overlooked voices that do similar things, diving through primary source material and data and uncovering very important stuff that's gotten ignored. Occasionally, I've seen these people break stories that eventually get the attention of the national media - but it's hard, and this usually only happens for the really huge stories.

Meanwhile, the big players in these spaces are usually intellectually incurious and busy churning out vapid engagement bait.