You're right - there's no doubt M$ would be happy to use these for offensive purposes. They are evil, after all. But our patent system encourages this behavior whether or not you're evil. If you aren't able to throw your weight around in this arena, there are other evil corporations who are, and they will use it to put you at a competitive disadvantage.

My opinion is that focussing our hatred on M$ in this case is treating a symptom. Let's fix the patent system so that this kind of idiocy isn't possible or necessary.