It's not okay to attack people for being different, or holding different opinions.
However, there's a very fraught dilemma -- how do we balance between personal autonomy and enough backchecking to minimize ghastly mistakes? Many transpeople suffer because gatekeepers prevent them from reaching the care they need, and some of them die from it. Not to mention the damage of knowing it's not really your body anyway, because you don't get to make the decisions about it, someone else does. On the other hoof, transition is a challenging process, not something to rush into or through. People can get hurt that way too.
How do we find the path that does the most good and least harm for the highest percentage of people?
I was glad to see another perspective on the topic of genderspace, too. A lot of feminine people really don't feel comfortable sharing a bathroom or locker room with someone who has a penis, regardless of how that person identifies. Transpeople are far more likely to get attacked in or near bathrooms than anyone else, but it happens to women too. And beyond that, everyone is subject to another issue that appears when people resist using bathrooms because they are unsafe or unclean -- it runs up the rate of certain health problems.
The best solution for this that I've seen is dotties. A single lockable cubicle is available to everyone who doesn't wish to use the gendered bathroom. They really need urinals, though. Put it behind a screen if people don't want to look at it, but that's better than the problems caused by men who can't hit a toilet.