There's no analogous question regarding homosexuality.
They in fact have in the past.
But yes, if the activist community fails to disassociate itself from / speak out against radicals who are harming people, then that activist community is going to receive criticism.
I sort of agree, in that the groups are composed of individuals and it's not entirely fair to hold them responsible for things they didn't personally do. I also think if you see a political community as having some sort of problematic culture it's reasonable to say so.
Also? There are trans women who say I'm a trans woman who hides behind nonbinary to avoid the difficulty of transitioning. That position is just as harmful and ignorant, and I still fully support binary trans people. That some people are butts is not an excuse to dismiss an entire group of humans.