You write powerfully, but I think the core of your argument is a logical fallacy.

It rises most obviously in the quote above--some people who otherwise would not be safe will be safe. What is wrong with that?

That you do not achieve safety for everyone does not mean there is no value; only if you achieve safety for no-one is it true, or if you make some safer while making others necessarily less safe it's also true.

At the very least it needs an argument that saving some isn't a good thing, and if you want to save everyone then you need to have a discussion about how this can be achieved: do you have additional structures to protect the still-unprotected, or can you change the existing ones to be more protective?

Now, if you want to make a different point: "it is not in my self-interest to advocate for a safe space that I am not personally safe in", sure, of course, that makes sense to an extent. (Though people do tend to wish that men would support women's shelters, for instance, so you can definitely take the not-safe-for-me thing too far.)

But if we're discussing the situation in general, that you're unmotivated doesn't make it a bad idea. Nor does a solution being incomplete make it a bad idea unless it's actively preventing something better.