@ganymede Normally getting farther in the playoffs is a big factor in MVP, but I think this year it was different. It was what they did against the Warriors that was the tie breaker - because I think it was pretty close. If not for the fact that they both played the Warriors in the playoffs there would be a lot more speculation and what ifs.
Your point about Lebron having better numbers and Harden having Chris Paul is an argument FOR Harden. Of course Lebron had better numbers, he had far less talented help. Houston spread its numbers around but even then Harden still had great numbers.
But when it came to playing the best team in the league, Harden (& Co.) got much closer to getting the job done. Harden led especially well, putting it to the Warriors - even without CP3 when they met in the playoffs. LeBron was outstanding, but he couldn't lead his team to even a single win (thanks to JR). And if not for Houston's game 7 3-point shooting nightmare, a CP3-less Harden-led team was poised to put the Warriors down and ultimately take the championship. LeBron was never close to that this year.
MVP is an ambiguous term. But I think that can be good. It offers more variety than simply 'best player'. I do think LeBron was the best player, just as he is every year. (But that title gets kinda boring year after year.) But his value to the Cavaliers was capped. I think they exceeded their potential because of him, but they were never getting past the Warriors. The Rockets, meanwhile, had a legitimate shot of taking down the champs, but only thanks to Harden (especially shown with CP3s injury in that series), making him more valuable to Houston than LeBron was to the Cavaliers. Their play against Golden State made the case for Harden.