As much as I applaud the effort made to include more diversity in TV shows and movies, writers shouldn't forget that most people don't watch TV or movies to see whether black women are included or a transgender character is actually portrayed as someone with real thoughts and feelings. They watch it because they want to be entertained and crave a good story and good characters that relate to them.
I went to college for screenwriting and while I did take a Race and Gender Images in the Media course, I was more interested in the courses that actually taught me how to outline a screenplay, flesh out my characters, and make my narrative structure sound.