A professor has no pull on an external site. But they can certainly raise a stink within their university.

When I went to UCSD back in the 80's there were the CAPE (Course and Professor Evaluation) books you could purchase. At the end of each quarter, questionnaires were left outside each lecture hall, and collected by a team of entrepreneurs. Some profs allowed the CAPE team to explain the how the rating system worked, but others just tolerated having the questionnaires distributed outside of class. In theory, UCSD could have prohibited this on campus, but they didn't. CAPE books were funny, with great comments and interesting artwork created to illustrate some of the funnier comments. But that was a different era, and physical books weren't as easy to disseminate compared to an website that shows how bad or good a prof/course is.