I am a Lakers fan, but haven't been following them or NBA in general that much lately.
But, why would Lebron and Carmelo be bad for Lakers? They're amazing players.
Any rumors about PF/C? I think they need someone at that position badly.
#1) They are both 30, and will be looking for max contracts
#2) They still have one Kobe Bryant on the team, and I find it near impossible that they will all be able to play together. Three alpha males on the same team? It worked with Shaq and Kobe because they were both much younger, and played two different styles of ball. Imagine these three on the same team

. Lebron will want to end up killing the both of them, and I can't say that I would blame him.
#3) They would literally have nothing else on the roster. As I had stated earlier, they have sold/traded away every 1st round pick they have had since 2007, and in order to try and get Melo on board, they would need to trade that #7 pick as a sweeetner to a Steve Nash trade. Therefore, they have no youth on the squad, no young legs. Hell, they only have Kobe, Nash, and Robert Sacre under contract.