I think there's cognitive dissonance here between the ease of committing torts on the Internet and the severity of the penalty.
If someone physically stole CDs out of a publisher's warehouse over a long period of time, the marginal cost of those CDs is so low that the damage would be roughly equivalent to what a filesharer does. But nobody would be up in arms about a six-figure judgement.
But on the Internet, we all know that the same tort is a couple clicks away, and that it's widely practiced. So there's outrage and surprise when the law works the same way against those filesharers.
I guess I see things a little differently because my career has been spent in close contact with other torts that, while far more damaging than file sharing, are often just as simple to commit. Nothing stops you from sharing files, and so you feel somewhat entitled to do so. But nothing stops you from crashing any number of important web applications, either.