It comes from the same place the words you just read came from - contempt for a system of thought that deforms thought and degrades humanity. In Weinberg's case, he objects to a moral system like the one I just described, where good people can be convinced to support irrational, destructive doctrine. Sure, you don't like reading that, but does that matter if you can't rebut it? Why should Weinberg or any other humanist mind provoking people who buy into such a system? The purpose is to inform others of what this church is and does, and to convince whoever supports freedom and tolerance that church doctrine is antithetical to it.
This forum is a part of the marketplace of ideas where people make arguments like these. That's one of its purposes notwithstanding the implication of many that it exists to promote religion - the ones who ask what atheists are doing on a site called Religious Forums. This, among other things, is what we're doing - promoting a fair and rational worldview that esteems humanity, human potential, and human opportunity through human development and maximal freedom.
That church would criminalize this discussion if it could. If it had the power to arrest me for a post like this, it would. If you disagree, please make the evidenced argument demonstrating the church's tolerance. That's how the marketplace works. Someone makes a case, and others who disagree explain how, where, and why. It's (uncommonly) called dialectic, but it's to give and take that defines peer review in science and courtroom trials, where opposing factions make their case before other experts in the field in the case of science and jurors in the case of a trial, each trying to poke holes in the other's case, until a decision is reached, the last plausible, unrebutted (or unsuccessfully rebutted) claim prevails.
And why is that? Because correct answers can't be successfully rebutted. That's one method for arriving at correct answers. Another is an idea's ability to predict outcomes, but that means that there needs to be a test of the idea. I say that Weinberg's claim passes both tests. It cannot be successfully refuted, and it predicts exactly the kind of behavior Handmaid's Tale we've been seeing lately.
So now, yes, you find Weinberg's comment offensive, but do you find it incorrect? Do you still consider it nothing more than a hateful, unjustified, gratuitous attack? If so, please explain how. Show how religion doesn't do what Weinberg says it does, and I assume that Weinberg had Western religion in mind when he made the comment, which is chiefly Christianity. And if you can find no fault in it, why are you objecting to it? Why aren't you promoting it yourself? I don't know how you'll answer this, but if you reject it all out of hand and continue framing antitheism as an unwarranted attack on a lovely religion, then aren't you an example of what Weinberg referred to? You would be from my perspective.
I hope you choose reason and compassion over irrational dogma. That's why I post like this. This is an argument appealing to your sense of what is good and right, and I hope it comes from a mature conscience and not an old holy book or a pulpit.