The short answer is jury nullification is an unavoidable thing. If matters get bad enough, it will kick in. (Though if things get that bad, they'll be eliminated.) That doesn't mean it should be encouraged.

The moment you let juries start deciding whether the law is just, versus deciding if a law was broken, you remove the veneer of objectivity that has kept our courts somewhat sacred. It also becomes problematic for lawyers to remove jurists for ridiculous political views, as it becomes a First Amendment issue. Currently, that isn't a problem--your political views don't matter. Only your objectivity does.