Right; the ethical experiment here would be to set up one's own private Tor network and then attack that. (Think that requires a lot of effort? Well, yeah; that's why you do it as part of a university with grant funding!) This would also have the bonus effect of being able to instrument all the nodes, so you could see the effects of your attack flowing through the system in a white-box manner.

Some of us are more outraged by the fact that they kowtowed to authority on the BlackHat presentation, and had a disclosure policy that favored the Feds over both the Tor project and the entire security community.

The CMU researchers are basically Sabu. Subhuman traitors to the hacker ethos.

I doubt they ever particularly cared about the mantle of 'hacker' and whatever ethos is supposed to go with it. That makes it hard for them to betray it.