I lived in Philly (though not at ALL an Eagles fan) during much of the Reid era, and I respectfully say you are over-evaluating his abilities.
I'm not at all saying "he sucks". He clearly doesn't. But that is not to say he's a great coach. He might have 11 playoff wins, but he has 12 playoff losses, and too many questionable series, like the one in the Super Bowl against the Pats. They were down by 10 with about 5 minutes, left, and sure, McNabb led them to a touchdown, but they didn't "no huddle" once, and burned almost four of those five and a half minutes in doing so. This is against a coach that actually LET the other team score a touchdown once, so he could get the ball back and wind down the clock.
He's won a ton of games, he knows how to establish a solid, consistent approach for his team, but in my opinion, he's not a top tier coach, and back to the discussion of Jim Kelly, if I'm starting an organization, I don't think he's the guy I pick.