he made kitty and rogue and Emma and storm and Jubi look like their cartoon counterpart.
While I won't say anything about personal preferences in regards to the appearances or aesthetics of any characters (appreciative or disdainful), I do feel like it bears mention that your comment here is objectively incorrect. For the five characters listed, only Kitty and Rogue resemble their canon counterparts from the cartoon. Emma and Storm have both been made significantly more voluptuous despite both women having been depicted as rather slender with modest to small busts and waists. Jubilee in turn looks nothing like her X-men Evolution counterpart (which is the cartoon this game is based off of), though admittedly does closely resemble her classic appearance from the earlier 1990's cartoon and the comics.
As for the design and personality divergences, steady decline of art quality aside, Oni has at least been upfront about them prior to votes for characters being added. Every vote has included both sketches of the characters, as well as an explanation of how Oni would plan to interpret them, which includes his rather divergent take on Jean, which was outright said to be a result of him not liking her and thus deciding to make her personality unlikable. Despite this people still voted for her and the other characters, even when they were clearly not going to be particularly close to their show incarnations.
Mind, I would argue that is a distinctly different issue from the decreasing art quality, since even compared to the sketches made for the votes (which for the most part date back to the first vote or two and have not been updated since) the recent characters have been worse.
The main point however, is that far fewer of the characters resemble their show counterparts than you seem to think (and in some cases that is due to supporter feedback, as one poster in this thread has claimed they gave feedback resulting in both Emma and Storm becoming curvier than initially planned), and patrons were generally aware of that when selecting them.
You also completely failed to mention Laura who is similarly divergent from her canon appearance, though in her case most people seem to prefer Oni's changes (a few animation issues aside).