First off ,I never said he was a great coach. I said he was good. It is harder to rebuild in the NFL, because most roster moves are made by a GM not the coach. Ask yourself what did Gruden take over. A team with an average offense and a great but aging defense. He won a Super Bowl with Brad Johnson at QB. Then he had Chris Simms, Shawn King, No Rb, no WR's, and a defense past its prime. What big name players did Tampa sign while Gruden was there? Jeff Garcia?
The fact is he lead the Raiders to the AFC Championship in his 3rd year, the 2 years later won a Super Bowl in Tampa with a team Dungy only won 9 games with the year before. Being the head coach of a Super Bowl Champion should not be taken lightly, it is a very hard club to become a member of.