A lot of people from YouTube are a joke. And like others have said are charismatic enough to have their own channel and do well enough with newbs and uninformed to make a go of it. Those of us that have been doing this most of our lives either don't have the time (waterchanges, making our fishes lives better so on), don't have the charisma to do that well, or the knowledge/ equipment to do well on YouTube. I started a channel just to post vids here, they are mostly just vids of fish and stuff.
I've forgotten who said Corey has only been keeping fish for 8 years but that is wrong. He's owned the co op since 2012 and has been keeping fish for a long time. He used to be a member here (guess he still is). I like Corey but think some of what he says is his opinion not cold hard fact. I also agree that besides the mbu puffers I know he doesn't keep monsters. I don't really either but I like it here more then other forums.
It was also said above that you need to take what most said with a grain of salt or in some cases a bottle of Jack and a bottle of aspirin. Not at the same time kids! Ive learned a lot from YouTube and think over all it's a good resource. You need to sort out the bunk for yourself though.