It’s catch and release, not life long milking. Granted, the survival rate isn’t as high as I’d like (70-90% apparently), but I do also appreciate having safe injectable medicines. All things considered, with a species bias, I’d prefer dozens of humans live at the expense of a… Not crab. Unfortunate though it may be. I can’t also help but notice you’ve anthropomorphised them a bit. I’m certain these creatures respond to negative stimulus, but attributing fear and life long trauma seems to be giving their intelligence a bit of an unfounded boost.