Because he wasn't greasing politician's palms. Take a look at Gates and Microsoft's political contributions before and after the anti-trust actions.
Giving millions of dollars to liberal causes isn't enough for politicians. The pols must have their take off the top.
It was because of the corporate stands he takes. He stands for a free and open market and against unnecessary government regulation. Gates may be a social liberal but he understands that business principles are seperate from personal politics. Like I said earlier... Does that make him a traitor???