What separates a stars "franchise" players is their multidimensional impact on the game. Players like KD, Davis, Lebron, CP3 and George are already exceptional at spring, passing, defending etc. So that they can affect the game in multiple ways.
On not-so-great teams with star players like the Wolves (Love) and Knicks (Carmelo), you have players who are good enough at two or three things that they offset the weaknesses in their game enough to constitute a star label. That's what makes the second tier necessary.
For me, the above players are the only guys I'd really have an easy time building a team around. You can go the way of the Rockets, however, and collect two really good players and build around them. But individually, a player has to have no glaring flaws to be considered a franchise player.
Edit: Pre-injury Derrick probably belongs on that list too, although I don't watch enough of him to know if he's a good defender. I would assume he is because of his athleticism and Thibs but you never know.