I get what you're saying but I don't think it'll stay that way for long. It reminds me of how people used to brush off blog sites but now some bloggers are considered legit reviewers. There's going to come a day when youtube reviews start getting listed on aggregate sites like RT, I'd bet money on it.
Do I want that to happen? No, not really. But yutube has changed a lot about how we process media though. I don't believe these guys are forced into just new/commentary and can't also be critics. In fact, I think that's what a lot of these guys are actively trying to do. The distinction you're trying to make would also fit something like Entertainment Weekly but reviews in that commentary magazine are taken "seriously" because they're written.