>>2789088I think it has something to do with its particular spot in anime history. It was one of the most relevant anime among western weebs before the weebsplosion of the mid–late 00's. After that it was gradually overshadowed by newer shows.
Western fan artists didn't really get on their shit until the 2010s, so for a good chunk of the fandom's history, what little art Ranma had was mediocre DeviantArt/Newgrounds shit—and by the time western artists stopped being so horrible, the franchise was scarcely relevant. Why would all the newer, better artists bother with Ranma, when there's this hot new Madoka right over here?
The situation's definitely improved over the last decade (There's probably more good Ranma art today than there ever was bad art then), but the franchise still has that baggage.