You'd make a much better point by referencing someone who made a string of hits over a long period of time only to greatly flounder. Ridley Scott ain't that man. He's alternated between high and low quality projects his entire career.
Call me crazy, but I think I can count on a man who hasn't disappointed since he hit the scene. Is it conceivable that Brad Bird can make a lackluster movie? Sure, but I wouldn't want to be the idiot to bet against his track record.