I once again believe you can criticize this person's argument without that. Perhaps going into why you feel religion isn't stupid.
It was too meta for this forum sorry.
I just think that a large majority of people always have a sense of wonder, and can't help but think at the beauty of it all , at the sense it does, as why we're here and what were before us. And then another large majority of people need a sense of community, of being part of an order, of having structures in society that cannot be broken.
The formers are spiritualist religious people. They don't believe in rules, they believe in the "beauty" of nature if you like.
The latters believe in order, and not in people. They want to believe they are part of something important because they can't see importance in the beauty of nature itself. Those are the majority of the "religious" people of today. Which i'd argue are really not religious at all; more like bind in cultural and societal dogmas, not in the exploration of the self and the unknown.
The problem here imho is that modern "religions" have all a basis in the spirituality that more or less all human have, but use it only a pretext to justify societal structures, and not push toward those feels we innately have. The simple idea that something can be true always for such fickle, variable things like human societies and moral values require you to refuse any change for the worse but for the better too, it deny progress itself, it's a dead branch in the evolutionary tree of ideas.
So no, i don't think religion itself is stupid because i think a lot of people used it a source of motivation. Many scientist of the antiquity like Galileo itself was drawn by the conviction that things had to be simple and elegant because a creator god did them, but in general, it's a more primitive instinct. It wasn't religion that put in prison, it was the church a very temporal power. Einstein was pretty similar, and his faith in a perfect order was so strong that he rejected Quantum Mechanics for many years, before the actual implications of the theory were clear.
The discussion on God is really similar on the discussion on numbers in a sense. You can't prove that either exist (it's an interesting discussion, the one between idealists, concretists and symbolists i believe, i dunno the exact english denomination for those three train of thoughts). Well, at least number works.