The thing I never liked on DPR is when someone says something negative about a product on a brand forum and other people perceive this as some kind of attack on the brand and respond aggressively with personal attacks, impugning motives and so on. My opinion is that as long as people are civil and polite it's fine, but when someone goes on the personal attack and their attacks get defended by other partisan forum members, things can get nasty quickly. It's important that mods step in quickly, take the participants aside and say, "you know the rules, we don't allow that level of rudeness here. By all means continue to debate your points but cut out the personal attacks whether out of malice or simple frustration". It's rarely rocket science: most people can easily see where a conversation is going pear shaped: "you're nothing but a dumb shill", "and you're a troll who doesn't even use the [brand]" etc etc.
What I don't like is mods who feel it is also their job to defend the brand, rather than maintain order. It's no good if a mod lets positive posters about a brand get away with anything, while clamping down on posts they simply don't agree with but are actually reasonable posts. Not sure who "watches the watchers" but ideally there will some kind of amiable arbitration process of disputes between posters and mods long before it comes to handing out bans.
I only got banned from DPR once in 23 years (just for a couple of days) but it happened because I said something about a product that caused the brand defenders to pile in on me in a mob and say some pretty robust and personal things about me. The problem with that ban is while I did start the fracas by saying something negative, it was truthfully negative, and the fuss was caused by angry responses of the brand defenders, not me. It stopped being a discussion and became something that was declarations of loyalty. I was the only one involved to get banned and without a word said to me about why, I just suddenly found I had been silenced. All rather unsatisfactory. Please don't protect aggressive and rude brand defence over civility, even if other posters get annoyed by someone's views. Remaining civil should be mandatory for all posters.
On the question of more serious issues like racism, misogyny etc that does need to be stamped on, but there should always be a route of discussion open to participants with mods to get crystal clear what is and isn't permitted.
It's not always easy, especially when tempers fray, who would be a mod, eh?