Generally people don't embrace junk science after they clearly recognize that it's junk. The problem comes with allowing too much junk into one's head in the first place--too much stuff that isn't carefully checked. If you challenged David Buss, for instance, on the fruit fly thing, I expect he'd either come back with some other papers that do show the effect (for a fun role-reversal, this one with spiders, maybe: https://pubmed.ncbi.nlm.nih.gov/27249787/), or agree that this isn't properly experimentally validated.

I can't answer why people take seriously fields that allow a lot of junk. I'm not convinced that EP is particularly an outlier among the social sciences, though.