"And things usually degenerate from there"
No, this is where the real social justice begins. Because after that display it's only a matter of time before plenty of people will start to ignore Blue thus declining their impact as time goes by.
This is also not a good example in my opinion. Everyone who has frequented forums (even those who moderate swearing) will have run into a situation where one person gets offended by what another person says. Even though that person might not have intended that in such ways, but was merely pretty direct. To use your example:
"Blue: Lovely fucking day, was that all you had to say or are you going somewhere with this?"
This is the kind of response which might offend plenty of people but which, in my opinion, is no direct need to take offense. Sure it's direct and definitely cynical, but you also got to keep in mind that not everyone has a way with words. This Blue guy could provide tons of interesting and good facts in other discussions, making him well known (or notorious? ;)).
My point: a "friendly and fluffy" site would probably filter out those messages. They're not calling names, they're not belittleling people, but some people might find them offensive. Well, I think it's a good thing that some places have raised that bar a little.