I think it came about in 1999 and 2000 when the two teams played each other in the playoffs. It died for a while, then just came back about four years ago. I always love early season games when someone like Swift Current comes to town, and all 16 year olds on their team gives a "WTF" look when we're chanting about how a team that isn't even playing sucks.
A couple years ago, in Kootenay, they played the jingle that leads to the chant, only to have the Junior Hockey Junkies blare out "KOOTENAY SUCKS". The Ice never played that again.