Because nowadays, that's pretty much the only way to succeed in any form of content creation. * Getting people/companies/sites with thousands or millions of viewers to share your work, and using their audience to bootstrap your own.
This guy obviously doesn't have that. So no one's finding his content, even if they'd enjoy watching it.
Or at least he didn't. Since thisa rticle was posted, his channel's gone from about 2000 subscribers to 12,000 subscribers, just like how it'd gone from 100 to 2000 once it was posted on those deep into YouTube style subreddits.
So he's finally getting a following, because people now know he exists and makes videos.
* For 99% of creators anyway. There's always the 1% of people who strike it big from pure luck/timing alone, usually because they managed to catch an upcoming trend before it hit the mainstream.