Non hetero had more than 10% representation now I'm tv and movies especially tv. The estimates are 20% much larger by about 2x than the actual non hetero population. I have no trouble with representation I do have a problem with over representation and changing established character to make a statement which is what modern writers want to do.
Heterosexuals have been the focus of society for pretty much its entire existence, probably around 10,000 years. I think we can handle them taking a seat more towards the middle of the bus for a while. Those who've not been represented, misrepresented, and outright abused deserve some focus for a while.
Again, relax, heterosexuals aren't going anywhere they just might -gasp- not be the focus of attention in a TV series or movie here and there. Stop clutching your pearls, you'll break the strand.