I think you are misunderstanding the selection bias. We're on HN, the selection bias here is that people tend to be more tech savvy and more informed. We have nuclear scientists here. You typically see acidburnNSA commenting in all these posts. I myself did radiation shielding research for NASA at a previous job. There's an old saying in the nuclear industry "Those that know the most, fear the least." I do not think it is "big nuclear" but rather that we're on a tech savvy forum. Take this to Reddit. You'll find more generalized forums are pretty anti-nuclear and more scientific forums are pro nuclear[0]. It really seems to come down to more where the conversation is taking place. I've met and worked with many climate scientists. I haven't met one that is anti-nuclear (I've met a few that think we don't need it if things keep progressing). If you press them on the subject most will just say they gave up because there is no support.
[0] I'll add that there's a lot of armchair talk and just ignore people that scream that Thorium is the answer. Easy way to pick out an armchair scientist. (Yes, I get frustrated with the armchair scientists that are even in my camp. Really moreso)