Code can, in theory, be made largely unhackable. The more features it has, the harder it will be, and there's always the five-dollar-wrench hack, but nothing in theory prevents people from securing the code.
The law is always going to be hackable. Any significant law is always going to be far more complicated than code. It's dealing with people, not computers, who have far more different modes of operation.
The law will always end up relying on a certain amount of goodwill from the people. We'd love to have the law say, "Look, just don't be an asshole," but defining "asshole" turns out to be tricky, and there will always be somebody willing to be just-asshole-enough to be legal.
Worse... the law is retroactive: if you break it, the courts do something. Computer security prevents you from doing the illegal thing. That inherent delay creates inherent injustice. The delay also costs money. We've seen time and time again that it's been cheaper for companies to pay the extortion than to defend against it.
So I think that yes, they are evil, and not merely hackers taking advantage of a broken system. Even the best possible system is imperfect. We rely on human beings to engage in a certain amount of decorum, if only for the game-theoretic reason that too much incivility results in a breakdown and they lose.
Frequently, the patent trolls are breaking the law themselves, and counting on the delay to get away with it. That's pretty directly evil. And taking advantage of ambiguities in a system that must inherently be ambiguous, I'd say that's equally evil.
Simply calling them "evil" doesn't really accomplish anything, of course. But it doesn't make them smart. The system is easily hacked. Anybody could do what they do. They're more akin to script kiddies than hackers.