I don't think there's any particular trait exclusive or more common from one group to the next, other than maybe PC gamers tend to be more tech-oriented and are into modding and such. You've got cool folks and toxic people with every group. I'm opposed to categorizing separate "groups," as every individual is different and these broad strokes over millions of people is usually misguided and just cherry-picking certain types anyway.
You *could* of course make the argument that each fanbase tends to have different tastes and sensibilities which is natural as each company/console typically stresses different attributes/genres. Sony gamers are likely to favor more epic, cinematic experiences. There's a good chance MS gamers are going to favor FPS. PC is strong when it comes to RTS, Sims, and MMOs (along with FPS as well) so those who stick with that are likely to be into those genres. Nintendo is usually platformers, party games, arcade-style romps, etc..
Anyway, I was pretty much Nintendo exclusively from like 1990 or so when I got into gaming up until 2005 when I got my Xbox 360. Though I dabbled in PC and Sega as well at this time. Post-2005 I've pretty much been split between Nintendo and MS, with months or even years of leaning more towards one or the other depending on the console and games. Like in the dog days of Wii and most of Wii U I was definitely rocking the Xbox far more, while the early days of Wii and much of Switch so far it's been at least slightly in favor of Nintendo.
Only consistency pretty much for me is that I was just never much of a Sony guy.