Alright, here. I AM a lawyer (though not your lawyer, and nothing I post here should be construed as legal advice) and you might be interested to know that Microsoft is already backing off a bit in the suit with Barnes & Noble. So yes: "at least 6 multi-billion dollar corporations, some of which are much larger than Microsoft, have signed patent deals worth hundreds of millions over completely flimsy ridiculous patents that could easy be overturned by any court."
The nice way of saying it is that those companies have agreed to "play ball" and probably anticipate improved relations with Microsoft as a result. In the sense that it takes money to make money, these companies probably see the payoff as an investment in something else (even if that "something else" is just avoiding a protracted legal battle). Barnes & Noble is no stranger to the game of David & Goliath, though they are usually the Goliath! But they are refusing to be bullied while several of the companies who have capitulated are not treating it so much as being bullied as cutting deals.
If Microsoft hadn't insisted on an NDA ("you're violating our patents but we won't tell you which ones unless you sign an agreement with us") they might have some minimal leg to stand on. As it is, though, what they're doing looks an awful lot like bad-faith extortion. Especially if it was a natural person doing it; but of course, large companies these days get away with much worse.