Maybe I'm having a good experience, but most of what I've been doing is institution v institution. Institution v individual-which covers stuff like foreclosures and PI-is typically given to smaller firms because it's inefficient to ask biglaw to handle smaller matters, even relatively cheap biglaw places. The closest thing I've gotten recently is an indemnity action against a (different) manufacturer in a PL case.
I tend to agree that it's an issue on large-scale stuff like union busting, tax rates, etc, but that's a firm specific thing, and not one that always ties cleanly to biglaw. In fact, I've worked on two cases in which our victory resulted in higher taxes for the corporations involved. In both, those corporations were represented by smaller firms.
So, yeah, Im not going to dispute that Biglaw represents villains, but not necessarily for the stuff that makes them villainious. Compare me to a vet for Hitler's dogs, if you like. (Trump, of course, does not have dogs or a veterinarian for them).