As I've said before, I think the major issue the forum faces at the moment is racism. It's not many posters, but they flock to any thread that has a race angle and post some pretty insidious stuff. On the plus side, there are also group of posters who challenge them vigorously when they are out and about. But it can get rancorous and personal. Given the nature of the issues, that is no surprise.
On a related subject, the belief among some that we have left wing cadre that dominates things mystifies me a bit too. In just don't see it personally, and the fact that some posters take against demagoguery doesn't make them left wing per se. Not in my book, anyway.
I do think people are more opinionated than they used to be. I also think that people are more innately prejudiced - by which I mean biased - than they once were. I think that is a product of the explosion in social media. It is very easy these days to take your "news" exclusively from sources that tell you what you want to hear. Do that for long and you are going to get less open-minded, not more.
There is a certain amount of bullying - not much, but speaking from personal experience, it is not nice when you are on the receiving end. I'm thinking mainly of posters like Cat ; I think he/she can be irritating and one-dimensional. But he/she rarely breaks any board rules, as far as I can see.
There is also an issue around personal self-awareness, I feel. Some people don't realise what kind of persona they project, or don't care much if it rubs people up the wrong way. That also adds to acrimony, probably.
One last thing - whether the OP is "lazy" or not is hard to judge. It must have been prompted by something. I think it is ironic that that criticism is levelled by one of the posters I would say is part of the problem group. But that's just my opinion.
The mental health thread shows the forum - and us - at its/our best. There is plenty of decency and compassion about. It just tends to be harder to notice it amid all the noise and the nonsense.