I can think of lots of people here of "reasonable decency" besides kraftie, C2V, Alex; there's also people like Tanaka, B19, BeaArthur, Raleigh, ASPartOfMe, Adamantium, Skilpadde, Fnord, OliveOilMom, redrobin62, nurseangela, Ezra, dianthus, Hyperborean, auntblabby -- these are just off the top of my head, and I'm forgetting many more people who I would include if I didn't have short term memory issues.
These are all examples of people who are highly intelligent, calm on here, post rationally, and even in a disagreement they remain respectful and logical rather than oversensitive or losing it. I don't think I've seen any of the above, or the many others I know I'm leaving out but who would also be on this list, get emotional or unable to engage rationally.
Trust me there are many more people even than these, although I guess it depends on where you go the most. Love & Dating, and Politics boards have a lot more intensity going on. Not that General doesn't get sh!t happening, it does, but if one were to hang out the most on the more incendiary boards, you might not get to see all the calm posts happening elsewhere.
There are plenty of calm people on this site, and more than I expected given that we all deal with something that isn't always conducive to coping well.
The fact is, it doesn't matter where you go, there will always, always, always be some people you like and respect and other people you can't stand and don't want in your life. That goes for forum boards, the local cafe/hangout, a group of friends if the group is big enough, a workplace, school, everywhere.
The best anyone can do is try to overlook the people they don't like and concentrate on the ones they do. There IS no collection of people comprised of all-perfect people nobody will ever dislike. That's one of the sad truths of the world, we are forever destined to both dislike and be disliked, like and be liked, but who does either of these is a different set of people.