Because the fans who pride themselves as being smarter and more enlightened than the average person are just as backwards thinking as the worst of us?Yeah. That's the point. Sense8 has "a" transgender main character. Not "the" main character.
Currently, Sonequa Martin-Green is "the" lead character of Discovery. If they make her transgender, she will be demoted to "a" main character pretty fast. And the next square-chinned white guy who's already cast will become "the" lead character. Simply by virtue of executive meddling, reaction to fan-outcry, and the more ugly corners of the internet.
And I would like for Sonequa Martin-Green to remain the main character.
There is a sad, real-world reason why representation in fiction only progresses in baby-steps. Having a female and minority with a male name as "the" lead character for a flagship series is already a major step. I simply don't trust the producers daring to "risk" more and follow through with it.
Because Star Trek got us to accept a captain who wasn't Kirk, a captain who wasn't white, a captain who wasn't male and almost got us to accept Scott Backula. They would complain at first, then get used to it and pat themselves on the back for how great they were.
That said the character isn't trans and thinking that because her name is Michael is not only very misinformed about trans people, but silly.