There is nothing wrong by including LBGT characters into movies and series. As there never was with blacks or asians.
The problem starts, when the character is forced into the show, just for the sake of diversity. Just like with older movies, where the cast is white, but there is one black character (mostly killed of first in horrors), so the critics shut up.
One example: there is nothing wrong if somebody includes a gay character in a movie. Show his sexuality. But if every time he has screen time he has to flount it to the viewers, unnaturally, like he is "special" for his sexuality, not for his abilities or talents, it's unnatural.
There is difference between natural diversity and forced diversity.