Kidd averaged close to 16 ppg in college. Marshall didn't even average 10 ppg. Kidd was a pure point guard, but he could also score when needed. His biggest flaw was his inability to shoot the three, which he later addressed.
Rondo might just be exposed next season. It will be the first time we will see him without three future HOFers around him. I think just about anyone could have played the point for Boston and looked good.
Players that can't shoot don't make it the NBA. Omar Cook? Sergio? Ed Cota?
Sergio didn't succeed because he was terrible. The guy had an inconsistent outside shot, yes, but he also couldn't finish that the rim. His offensive skills were severely lacking. He had a great feel for the game, but that was about it. Nate had him as the primary backup for almost a full season and he couldn't do anything with it.
Jackson had the advantage, like Rondo, of playing with some amazing teams. He as on the Knicks with Ewing, and the Pacers with Reggie Miller. The thing is, he was discarded by both teams. Pure point guards are great, if they can also shoot the ball.
John Stockton
Jason Kidd
Steve Nash
There's a reason why most of the "pure" point guards are also HOFers.... because you have to be THAT good to make it in the NBA as a passer, otherwise you're just another Ed Cota.