I loved Eli, but the whole "he made everyone around him better" argument I don't think holds any water. His last few seasons were terrible... not because he was a bad player, but because the team surrounded him with garbage. Look at Aaron Rodgers today and you'll see something similar (though Eli's teams were much worse towards the end). It's true that the players that left the team didn't do as well once they left, but that's because most of them were on their fifth ACL tear.
It's a team sport; your good play can make others play better, but that has its limits. No one guy is going to just automatically elevate the play of everyone else that much.