. . is not that they're idiots, but that they all think they're so much smarter than Microsoft.
Every company that signs up goes in saying "Yeah, We know everybody else got screwed, but this is different. We'll do just fine".
Of course, as we've recently seen, Microsoft itself isn't entirely immune to this attitude. "Screw Janet Reno, This is business, not Waco" - Steve Ballmer.