I don't care one way or the other "how" people root, I just grew up with the mindset as a child, these are the teams that appeal to me, now stick with them for life. And I have.
But people that root for local teams, what happens when you move? Or when the team moves?
Are you a Raider fan, then a Ram fan, then back to the Raiders, then nobody cuz no local NFL team in LA?
Are you a Hornet fan, then they move to New Orleans, so you become a Pelican, but then the Bobcats are created (local to you now) so you drop the OG Hornets, for the new Hornets?
Do you root for the Seahawks, Mariners, Thunder? Or switch to the Blazers as your "local" team?
What if you live in North Dakota? Do you just not follow sports?
The "local" fans don't make any sense, unless they just plan on living in one major city forever, and no teams move. *shrugs*