https://journals.plos.org/plosone/article/peerReview?id=10.1...
I've certainly had peer reviewers trying to get me to cite their own papers in my articles, however I've never seen an instance where a peer reviewer alleged that an article I've cited was by someone disreputable.
I have recommended some citations to be removed as a reviewer. It’s not useful to keep citing discredited articles that should have been retracted. Keeping them in new articles just makes them more likely to be read uncritically and further propagate bullshit.
OTOH, the argument is “the article is rubbish”, not some kind of as hominem attack because I don’t like the main author.