not evidence that anti-racism is irrationalI haven't argued that it is evidence of such. I've argued that your particular chosen method of combating racism is irrational under a few specific conditions: A) your position is reasonable and B) the bulk of the people around you are reasonable and just.
It seems like you don't believe B is the case ("I've already made it quite clear that I think not all the minds in question are reasonable.... [L]eft unchecked racism could fester in us and cause great harm...") and don't especially care if A is the case ("outside all reasoning...no matter how you or I react to racism...it is still wrong.").
Given you believe your heritage is at stake ("I'm worried because my children will have the same Jewish heritage I have"), your method is quite rational under those conditions. I wonder if your co-religionists tend to be of a similar mind.
You may as well ask me why I argue the sky is blue when someone tells me it is green.
Except you're not arguing against racism, you're arguing for outrage against racism. Those are two very different things.
It's strange someone would ask me why I argue the sky is blue
I'm not asking you why the sky is blue, I'm asking why you think outrage and censorship is the appropriate way to keep minds from thinking the sky is green. From what you've said, the answer is that A) you feel the stakes are quite high for you personally, B) you didn't reason yourself into the position that the sky is blue, but in fact believe it's outside the bounds of reason to even weigh in on the subject (I suspect you don't actually think this, but it is what you said), and C) believe a great deal of the people around you are mentally deficient in such a way that they're biased toward belief in a green sky.