Silva's not wanting the light heavyweight title isn't the point. You don't pit a champion, main event fighter against rubbish. Silva is a middle weight, and the UFC should figure out a way to get him in against more top tier fighters, whether that means others lowering their weight or him stepping up. I blame the UFC because it's in part their job to make sure fighters are fighting who they should be, not just who they want to (for reasons of camaraderie, as with Machida, or because they want to take it slow).
I actually think that quote by Silva, about his wanting to test himself at LHW, is kinda bull -- to me there didn't seem any question he would be competitive at the weight class. The guy wants to get into boxing, well, he should watch the Pacquiao/De la Hoya fight a few times. That's how you step up in weight when you're a champion.