that's got to be the most ridiculous theory I've heard since the flat earth society.
He wasn't going to win in 2004 for Pirates because Pirates was a light weight movie and he was going up against Sean Penn (whom everyone felt was overdue to be recognized.)
He wasn't going to win in 2005 because Finding Neverland was a mediocre movie and, frankly, his performance was the weakest in the field that year (Jamie Foxx in Ray, Don Cheadle in Hotel Rwanda, Clint Eastwood in Million Dollar Baby, and Leonardo DiCaprio in The Aviator)
I haven't seen any of the nominees this year, but Daniel Day Lewis consistantly gives performance after performance that completely blows the audience away.
Johnny Depp always gives a fun, charismatic, quirky performance. I certainly think he's got a best actor performance in him. But, he hasn't hooked up with the right role in the right movie in the right year yet.
Quit looking for conspiracy theories when there's a much more obvious explanation.