I have a comparison between me and a friend at a different university. Both of us took Organic Chemistry and both are Pre-med.
For me: The way that the professor taught the course was incredible. On the first day, he explicitly said that Orgo should not be a weed-out course, and that he's not "expecting" people to fail. His class wasn't easy; in fact, it's probably one of the hardest courses ever (as organic chemistry probably is for most pre-meds). He was always open to questions and encouraged team-based learning, including my university's peer tutoring system. If you went to office hours, he'd write your name down for future reference so he knew EXACTLY what each student needed throughout the course. He was passionate about making sure his students didn't just memorize the material, but rather truly understood it. (For example, each student bought this ball and stick model molecular set that we used during exams and practice problems to help us visualize what was going on). He was also consistently receptive to feedback from students and emphasized clear communication of the class expectations. The average for the course ended up being a B+, across like 80-100 students. He has a near perfect rating on ratemyprofessor for all the years he's taught. And the end of the course, all of us stood up and gave a standing ovation and cheered for him for like a solid 5 minutes (not exaggerating).
For my friend: According to them, the professor didn't help students at all. Her class averages were consistently 35-40% across the board. She didn't help them with anything, wasn't receptive to feedback at all. Dismissed all student concerns as well. (I think she went on probation after that year, but I might be misremembering). Half of the students failed the course, and my friend (who is a whiz at chemistry) ended up with a B- (the ONLY grade that they had throughout university that was less than an A).
From these two examples, I think that a professor can make or break orgo. The content is hard, but if taught the right way, most (if not all) students can succeed (as long as they put in the work and effort to do so). I'm not saying the NYU professor necessarily shouldn't have been renewed (I didn't go to NYU so I don't know how much it differed from my university), but if there were consistent problems throughout the years, then perhaps some action should've been taken. That's just my 32 cents though