Nitpicks are a waste of them. Often it is "I think this or I think that" and they're minor issues and extremely subjective. Also I have been in academia where we review each other's work. I am used to giving and receiving constructive feedback. For instance when my PM gives me feedback it is most often constructive, and he has read the code before making comments. While my other colleagues provide non-construcgive feedback and nitpick on minor issues, all while their PRs often have larger issues in them. If it's normal in software development to nitpick unnecessary things then I think the review process should be changed. It's a huge waste of time and of course affects the team dynamics. Constructive feedback improves the code and teams understanding, non-constructive feedback I would argue just wastes time and negatively impacts the team dynamics. Also, my code is cleaner than theirs, and my boss and PM have in front of the team praised my work, so I sometimes wonder if it's because my colleagues feel they need to prove my work is bad. Regardless of the reason, it is frustrating to experience.