Okay it's a bit of a fair point. I just think when a community and organization give athletes these contracts that they have somewhat of an obligation to said community.
I see your basic point here. Although, look at LeBron while he was in Cleveland... he really had no obligation to the team itself, let alone the city. Gilbert pretty much let him (LeBron) do whatever he wanted without putting any actual expectations on him. He let him dance around like an idiot in the pre-game, say and do whatver he pleased, and gave him all the money and praise (deserved or otherwise) in the world.
I would say that Gilbert, Mike Brown and the rest of the Cavs' front office are to blame for not cultivating any sense of obligation in LeBron. And really, what does anyone expect? He was (at the beginning) an 18 year old who was given millions upon millions of dollars, praised as the basketball messiah, and was never made to actually produce results. Having all of that as a teenager, with neither incentive, nor expectation to change, or grow as a person he essentially stayed in that mindset that he could do whatever he wanted without fear of repercussion or feeling any obligation to the team or town, which ultimately led to his eventual departure from Cleveland.
Was it (his leaving; the Decision, etc.) a bit self-righteous and immature in its application? Of course. But, no one ever held him accountable for anything in Cleveland, it was always an attitude of "LeBron can do no wrong," and it was always "someone else's fault," that the Cavs didn't succeed. Place no expectations of obligation to anyone, or to anything other than oneself and that's exactly what you'll get.