Why do you believe it was worse when Bush left than when he took office?
GDP was negative when he was sworn in. There were 3.5M jobs added in year 7 of Clinton bringing the unemployment rate to 4.0%, but just 42,000 jobs added in year 8 with unemployment jumping to 4.7% (that's near 20% increase). In spite of a multi $billion stimulus package of his own, plus various other measures, it took 2 years to turn the tide (unemployment went 4.7% -> 5.8% -> 6.0% -> 5.5% and down from there).
The Dot Bomb bubble burst in year 8 of Clinton, costing $7.1T in net wealth to everyone in the economy, as an aggregate. The banking and real estate collapse of 2008 cost $5T. Which was worse?
After 9/11, the airlines industry needed a bailout. American Airlines was forced into bankruptcy. Bush "saved" the entire airline industry as much as Obama saved GM and Chrysler.
Look at the job losses Bush inherited.