^I see what you're saying but if you are from the city that the team plays in they represent you in a way even though its not on the same level as college. Plus when you have 20+ years of emotional investment its hard to break that. I could never just stop being a ******** fan, and
I don't care who in my family worked/played for the Cowboys I would never become a Cowboys fan 
I could hope my family member does well but I could never root for them to beat the Skins.
Its not really the same thing, but when players from my school get drafted I'm usually hoping they won't go to a team I hate. I didn't wanna see David Wilson on the Giants but at the same time I knew that was a good situation for him and was happy to see him go to a good team + big market. I already watched a lot of their games anyways since theyre in our division and I'd watch hoping for him to do well but the team to lose.
If it was another team that I'm neutral towards like the Niners or Dolphins then I could definitely start rooting for them as well, but they'd never replace my original team.