Not everone in PS is nice. Me, for instance.
I think that you're right though. PS does seem unique, and the community is a major reason. I will say though... I've been around some pretty heated D&D discussions before.
"No, you can't buy a cow and use it as a steed!"
>"But it's so much cheeper than a horse..."
"It's a cow!"
>"I could train it!"
"It doesn't work!"
>"Screw you!"
"And YOU, no chaotic evil characters this game!"
>>"@$^$#"
>>>"Can I be a pyromancer?"
>"A what?"
"An elementalist who specializes in fire."
>>>"Yeah."
"Sure. We'll just give you +2 to all dice rolls for fire spells."
>>"Uh..."
"It will be fine, he's new."
Later on, our camp was attacked by some footmen and some archers.
>>>"I want to cast lightning cone behind their line so that I fry their guys but not any of us."
>>"Wait, it's a freaking cone. We'll be killed."
"No, it can work if it's placed right."
>>>"Ok, and I'm going to cast fireball on those archers...."
"Ok, roll."
zanzibar has rolled a 6, a 6, a 5, and a 6.
"..."
>>"..."
>"..."
>>>"What?"