Yep... just ask Peyton... err... Ben Roeth... err... Matt Rya... err... Sam Bradf... err... Cam Newt... err....
The QB position is much like any other position. Sometimes, you get a player that is ready to get in the game, and get to playing. The experience helps them improve, and so long as the foundation around them is relatively solid, they can succeed and improve year to year. Sometimes, you get a player that has to sit behind a legend and learn until their opportunity comes. No one way is better than the other.
As a Colts fan, as much as they are anointing Luck as the next top tier QB, you never really know. If Manning comes back and plays another 2-3 years, I dunno how much sense it makes to use the top overall pick on a QB you plan to develop. If he's as good as they are saying he will be, you probably don't want to sit him at all.
The Aaron Rodgers thing made sense because the guy was the 24th pick in his draft. A QB picked at that spot isn't necessarily guaranteed a starting gig, so sitting him a few seasons makes sense. But when you have a HOF QB in Manning, and you use the 1st overall pick to select his successor when he may have 2-3 years in him... I dunno. I'd rather seem them take a Suh-like DT or shop the pick for a handful of others like a 1, 2, and 3, and a 1 the following season. This team has a helluva lot more problems than just QB. And if you want to give Manning a shot at winning another SB, you don't use a 1st overall pick to select a guy that'll ride the pine and do nothing to contribute. You use the 1st selection in the 2nd round for that, IMO. You develop a guy with all the attributes, that needs to refine his skills.
I am sure many Colts fans love the prospect of Luck. I'm not one of them. If they get him, I'll be happy. I just would like to see them shore up the defense and improve the offensive line.