That's BS. You Bill Walsh would have gotten a QB who couldn't run the West Coast Offense and revamp his entire offense around him? No! Just like Belichick, he wouldn't draft or trade for or sign a QB who didn't fit his system. His system. The system is in place. Belichick was looking QB that fit his system, not get a QB and revamp his system around him.
And the reason why Belichick was so quick to move on from Bledsoe was that never fit his system. He never loved Bledsoe. Bledsoe was obviously forced on him. Bledsoe was not passed his prime. He actually had a pretty good season in 2002. His team sucked, but he didn't. He just never fit on Belichick's system.
And yes, this is a QB driven league. Of course you need a QB. I never said otherwise.