To me the 'find a better spot' argument is only valid when you are facing a push with a marginal holding, Warpe's example is good here, or when your stack is at risk due to the nature of the villains betting i.e. you will be required to play for your stack on later streets. Other than these there are no other situations where picking a better spot is valid.

Why anyone here will play for stacks with a marginal holding against any opponent, loose or tight, is beyond my knowledge of what makes a winning player. Even if any spot you are in is slightly +EV why would want to play for stacks? It may be true that you may not get another shot at him, but isn't your long term success more secure if you are pushing with a better holding than AJ on any Jxx board against a loose or tight villain? Why should we assume that because he is loose that he does not have us beat? Only the bad of the bad that play with a full stack will raise a Jxx flop with only QJ, they usually just call you down. Maybe I am wrong, but there is nothing in this thread to make me think otherwise. I still believe that in these situations you CAN find a better spot.