Had they blocked Firefox users because of a security hole or layout glitch, that'd be fine--many of us have done the same upon finding somebody hitting our site with IE6 and requesting that they upgrade.
Had they blocked Firefox because it was a competing product (as Microsoft has done at times), that'd make sense too, although it's a bit scummy.
The problem though is that they've elected to block a particular browser based solely on the third-order actions of an employee of that company exercising their right to free speech.
Legally, sure, they can do whatever they want, but we really ought to hold them to the same standard we seem to be holding Eich.
Note, for example, that he sent some money into a cause and then the gears of politics ground and spat out what he'd supported--whereas fully 12% of people on OKC (according to their statistics) have been denied service on a whim.
Even from a business standpoint, why would you inconvenience 12% of your customers? That's just silly. Because you can get away with it, because you are a gatekeeper of part of their social graph? That's just scummy.
This is not how we should be behaving as a community.