bush wasn't blamed for katrina, bush was blamed for not seeming to care enough to get the federal government moving when hundreds of thousands of human lives were at stake. He was nonchalant as fuck about it and the government was slow to react.
Lifting humans out of new Orleans. Thats something that could have been done with simple manpower..We knew the solution as soon as the disaster happened was simply to get people out of there.
Lifting millions and millions of gallons of oil out of an ocean while the well is still gushing from the bottom isn't so easy. It isn't something that we are really capable of doing. We don't even know the solution yet.
Nobody can be blamed. Now, if there was a feasible method of fixing the problem, and Obama was wasting time and not doing what needs to be done to get that effort moving, then we could blame him.