I don’t know where you’re getting the “everyone” is rooting for the Pats but the only people I know rooting for the Pats have lived much of their lives in New England. Everyone else is either rooting for the “underdog” and against the Pats (pleading for someone to know them off) or else is indifferent to the NFL.
That’s my (limited) experience from out here in snowy Utah. fwiw (not much) I was born in and lived 18 years of my life in the Boston area, have rooted for Boston teams since the mid-60s, and although I often think I’d like to forget about their d####d sports teams (what an irrational attachment!), there is something about that youthful brainwashing as a sports fan that is very hard to shake!! So, all these years later, thousands of miles removed, I still take much enjoyment in the success of the Red Sox, Patriots, and now Celtics again, and much agony in their many bad years....... the Bruins I’ve never been able to care much about, even in their glory years long ago, I just don’t care about ice hockey.........
I think a lot of non-New Englanders are rooting for the Pats. I’ve never stepped foot anywhere in NE, I’m a Steelers fan, but I was 3 the last time a team ran the NFL table and I want to see history.