Because he only does very popular properties and spouts popular opinions. The target audience being kids, they are much less critical and demanding of content.
This is an international problem. There are lot of "cartoon" channels that have absolutely shit content, but are popular because they click-bait, and theorize about whatever's popular at the moment.
The few legitimate reviewers very rarely do current stuff that hasn't finished it's run. They mostly unearth very old stuff that is either hilariously bad or is a forgotten gem.
Out of English-speaking reviewers, I can only recommend Phelous: he's the only guy I know who's both informative and entertaining.