I don't understand why drafting Schrouder, or any other point guard, should mean that Rondo is tradeable. Even if Rondo is 100% healthy, he can't play 48 minutes a game. You probably don't want him playing more than 36-38 minutes, which means you need someone else for that other 10-12 minutes, and we have no one on the roster capable of that.
You draft Schrouder, play him as a backup for a couple of years, and then either keep him and move on from Rondo in 2015, or have a cheap backup that people are willing to pay a lot for, like Eric Bledsoe.
Seriously, the Pats drafted Ryan Mallett in the beginning of the third round, which isn't much different than the middle of the first round of the NBA draft, and no one is talking about trading Tom Brady. And Mallett is never expected to paly, whereas Schrouder would be guaranteed some amount of minutes even with Rondo as the starter. We need a backup point guard, and Schrouder shouldn't be looked at as anything more, at least not until he's proven himself on the court for a couple of seasons.