Cleveland's owner PAID for all of those things when he drafted and PAID LeBron. We do all have the right to go work for who we want. If I can't get a promotion at work because I'm not good enough - no one should fault me for working at a company where there is less competition among coworkers (thus, easier) but it doesn't mean I'm not less of a man for doing it.
Bron couldn't get it done. It's not just Cleveland's fault. I'm a big Mavs fan. Dirk can't get it done, hasn't gotten it done. Doesn't mean he's not awesome, and it doesn't mean it's the Mavs fault - He just hasn't gotten it done. And Dirk (I hope) will get his pay day, and he should - more people would like to see a loyal guy like Dirk win a ring than a guy like LeBron (who clearly can't) Dirk is older too, so had he left if the mavs were out of it I'd cheer hard for him to get a ring. 7 years? Dirk doesn't even think 12 is enough. Dirk's got unfinished business, Bron swept his under the doormat.
No one says he's a worse player because he left Cleveland, but you're a fool to think he'll be a better one for winning it elsewhere, as opposed to at home. And you're a fool to think getting one with 2 other "stars" (Bosh isn't a star, in my opinion, no star misses the playoffs 5 out of 7 times, on a decent team, in the East) is going to make him a better legacy.