Eh, it's comparable to something like an Actor or Comedian, they're producing a form of entertainment. And plenty of people enjoy that form of entertainment, and that's fine.
I think you might be surprised about how much background work goes into running a channel like this too, It's not just a matter of sitting down, playing some games, sticking it on YouTube. Also, at least for most mid-sized channels, it doesn't actually pay that well in the modern YouTube scene. I'd bet that only a small portion of them are really 'doing it for the money'. Usually it's because they enjoy making content that viewers enjoy, and the money is what lets them actually dedicate their full time to it.
Seems like a bit of an odd point to make when it's one of the few forms of entertainment of this type that's actually free for viewers to experience compared to something like a movie. And as above, they're definitely not getting 'free money', they're working a job and earning from it.
The dynamic changes a bit when you get to the extra large channel scale, but still a ton of time, effort and money goes into them to get them to that point and keep them going.