Geaux SEC?

I'm kind of tired of hearing all the "Hey keep it in the SEC" stuff. I don't understand it in the least. How can you cheer for a rival? I understand that ND is perennially overrated, and perhaps this will knock their favor in the media down a couple of notches.
But, everybody knows that the SEC is the best conference in football. I don't see a reason to cheer on any team other than your own no matter what conference they are from. Blood is thicker than water. I know this is my first post and I'll probably get ripped apart, but I thought I'd at least make it somewhat insightful.