Rule? There are no rules in fandom, only opinions.
Winnipeg is a unique case because we didn't have a team for 15 years. If you were 10 or younger when the Jets left, you probably didn't have much of a connection to them. So those people find a team they like in their teenage years or early 20s and there you go. That's what I did. But as soon as the Jets came back I was all-in.