No.
1. I love Steven Universe, but I'm not gonna lie and say it's perfect. It has pacing problems, a filler problem, hellish hiatuses, and a few other issues. Those are the criticisms I see brought up, not the LGBT representation. Throwing away any criticism of a show as homophobia is immature.
2. I don't even think those shows are the four with the most criticism (Steven Universe aside). I barely hear Korra criticism that goes beyond "it's good but not as good as TLA", and I hear basically nothing for the other two. I do remember seeing a lot of criticism for Star VS when that was wrapping up, and shows like Spongebob and the Simpsons are a fountain of criticism.