I agree with virtually everything written in this thread. Academia is a great profession for a trans person, but the tenure process is a miserable experience for everyone. I say that as someone who is very likely going to earn tenure in the very near future, and is going to go full time soon after. My chair and a few of my colleagues know, but the provost is not aware of my being transgender, and he won't know until I get written confirmation of his decision. I suspect he'll be fine with it, but on the off chance that he is biased, I want that letter.
That's the problem with the tenure process almost everywhere. Until you get let into the club, you are at the mercy of the administration and the tenured faculty, and the process is so opaque that bias is virtually impossible to prove. I do have employment protections for gender identity in my university system, but all someone needs to do is claim that I fell short in some area of my tenure application, and there's almost no way to prove that they wanted to get rid of me (for any reason). The criteria for tenure are typically too subjective to pin down, even if administrators claim otherwise. That's just the nature of the beast.
Now that I'm very near the end of my wait, I do think that it was worth it to stick with academia as a career, and to wait until tenure to fully come out and transition. Job security and a long summer out of the classroom is perfect for transitioning. But the simultaneous wait to transition and wait for tenure beat the crap out of me. I almost gave up on my career a few times, and honestly, that's fairly typical. Many people drop out of graduate school or go ABD. Still others get stuck in a rut of adjuncting and temporary positions and never get a tenure-track position. And it's more common than you might think for a tenure-track professor to get disillusioned by the process and give up, or just burn out. Add being transgender on top of all of this, and that's a lot of pressure to bare.
I'm not saying that it's a bad career. I love to teach at the college level, and I honestly feel like I am making an impact on my students' lives. The pay could be better, but I live a good life. If you can make it through the gauntlet, it's a very good way to spend your working years. And yes, I do think that academia is a very trans-friendly career. But go into academia with your eyes wide open. There will be times when you just want to give up, and plenty of budding academics are forced to give up, often through no fault of their own. There just aren't enough tenure-track jobs available for everyone who is qualified.