I hate when I keep seeing people ragging on "Colts fans" because of the reaction. I live in Colts country and I see way, way, way more people on my Facebook with "well that sucks, and I hate it, but I wish him well" type reactions than there people throwing hissy fits and calling him disloyal or whiny or not-tough or whatever. Actually I've only seen one or two of the latter.
There were like 500 people left at the end of that game and of those 500, maybe let's say half of them were booing. Big whoop. Aside from the culture warriors, who are gleefully grasping at this opportunity to "own the mils" there's not much meat on the bone with this narrative.
I do know that pretty much anybody here, if finances allowed, would love to retire early and pursue their passions, so you can't really take issue with a sportsball guy doing the same thing. Just because he has public visibility does not make him accountable to the public.