Microsoft sucks because of the proprietary software business model. That's the only reason. If Microsoft didn't exist another company like Apple would take its place. The only way fair and free computing can flourish is if we abolish the copyright laws that govern the distribution and use of programs, or if we all make a voluntary choice to just say "no" to proprietary software.
In my opinion, Microsoft sucks NO LESS than most other proprietary software companies. They are the natural result of this system. Please don't be hypocritical and stick up for other companies that are no better than Microsoft, like Apple, Adobe, Macromedia, etc.