I’m not sure where you’re getting this opinion because, aside from AskNSFW posts, OC posts are pretty much the only posts that consistently get actual comments. What do you define as “porn posts?” I’m imagining the professional large studio shots that get posted regularly. They get upvotes, but rarely get comments.
Yes. A common issue has consistently been that people will downvote all posts for a specific community or subject, whether that’s something gay, a specific hentai, or a more niche fetish/kink that they don’t personally find appealing rather than blocking it. These posts are usually relevant and quality submissions for the community that they’re posted to, but end up with negative scores because of differing preferences.