They didn't play WR or other rookies back in the day either. It was about rookies being in their place....It's certainly possible a QB should sit for half a year or full year, but I'm not sure it is necessary. Frankly, Young was a fine player, but never should have been taken this high at all.
There just are NOT 30 starting QBs on the planet, at some point, you gotta play that young guy and see if he's possibly one of them.