My opinion? I actually enjoy the fact that PokéTubers are feeling comfortable enough to be able to be more openly critical of the games, and have videos that highlight and focus solely on the flaws of different generations or specific games (both factual and opinion based flaws, btw). And while there are exceptions, a lot of PokéTubers cover both the awesome/favorite/best things about Pokémon as well as the problems/awful/least favorite things. Multiple PokéTubers I follow do this, especially "Everything Wrong with Generation ___" or "Why _____ Is Terrible" type videos mixed in with all the praise-based videos, and I never think they're awful for recognizing problems. In fact, a lot of these videos are enjoyable because they encourage you to look more critically at your own opinions and maybe see things you never noticed before.
Regardless of whether the video is positive or negative, majority of these videos also preface that is only their opinion and you are free to disagree. Everybody has their own unique opinions, and to be able to openly discuss these opinions is awesome. Being able to look critically at the games and see both the good and the bad even in your absolute favorite games/generations is significantly better than pretending as if your favorite is flawless.
Do I feel the increased presence is promoting hate or the idea of a fallen brand? No. Do I feel it's sign of being more open to different opinions? Yes.