To be fair ever since LBJ came on the scene, and to a lesser extent when the money entered the range of stupid, any sense of team loyalty has pretty much gone out the window. The absolute farce that was "The Decision" and how that played out set a new tone for the NBA in general, and showed all players that all that matters is their personal brand, and that they can force themselves wherever they want to go. The heyday of the 70's to the 90's where team pride and team loyalty were actually things that mattered are long gone in the modern NBA. There are small pockets of it, but usually only in cities where they have had recent success and aspirations to win more rings, such as with Golden State, and I believe Phoenix has built a decent culture of pride in the city and team, but that is the exception, not the norm. So Mitchell is just a product of the modern NBA along with every other borderline star, he wants to get his, as he sees his peers getting theirs. It isn't out of place and it isn't surprising in the least.
Actually the surprising thing is Rudy proclaiming that this is his NBA home and he wants to bring a championship here. And Joe's loyalty, which was rewarded with a ****** salary dump that actually won't save us much in the long run. Those are the outliers.
I am not saying it is just fine that this is Mitchell's approach, just that it isn't out of the ordinary and fits in exactly with the times. The days of any real pride in, or loyalty to, the team or city are long long gone.