Critics didn’t necessarily go to film school, but they see everything under the sun, so when a movie doesn’t do anything particularly new or is highly derivative without adding its own twist, it bores them. The person who goes to 3-5 movies a year doesn’t care, to them something derivative of 10 movies they haven’t seen is still new and fresh. This is in addition to the technical competency component you mentioned.

I watch a ton of movies so my tastes are more likely to align with those of a professional critic.