Enforcement is spotty, rare and takes so much time and resources that half the companies sued have folded for unrelated reasons before it gets anywhere near court. Plenty of significant companies you've heard of aren't compliant - I've been involved in getting Barnes & Noble and Viewsonic into compliance, and that's just stuff I've done in my spare time.

I'm not providing any kind of moral justification for companies behaving this way. But the fact remains that, given the current level of enforcement, it's cheaper to violate than it is to comply.