But because the majority of the public (in europe anyway) uses IE, as a web developer you can't mis IE compatibility.
I agree that Mozilla and Opera comply to W3c standards and IE kinda bends the rules, the fact that most people (in europe) use IE makes it the standard (in europe). So any big website had to make their site IE compatible even though it may disturb the way the site works with other browsers.
It may be that you find that IE is 'bad', the majority rules, and in this case in favor of IE.
I am not in anyway linked to the redmond monster by the way