I'll tell you why. In gameday chat we had weekly 9ers trolls. Some of them semi tolerable, but most hideous and awful. Taunts, racial slurs, hate speech and crap talking and trolling of all kinds. ALl year round. They were banned repeatedly but found ways around bans, and there were just so many of them it was hard to keep up with.
Not to mention here on the forums too, it was pretty damn bad all year round. Some genuinely came to talk shop, but most were here to gloat at our losses, and rub stuff in our faces every week, with snide little prissy comments and shots every chance they get.
When the cardinals lost the superbowl, I didn't gloat. I felt bad for them. I actually kind of wanted them to win the superbowl so the stealers wouldn't. They weren't horrible, intolerable A-holes to us all year, unlike 9ers fans. Atleast not on a grandscale.
So I don't feel bad for them ,and personally I don't think people are taking it too far. I think it's just enough. And hey........ it fuels an already heated rivalry.