We hear all the time about people taking advantage of tax loopholes, for example. Yet these very loopholes are generally designed-in, to push people into a particular behavior. For example, I could pay less tax this year if I had solar cells installed on my roof. Would you call this means of avoiding taxes a loophole?
Modern politics is, as much as anything else, about finding ways to coerce people into the behavior you want. We set up huge taxes on tobacco, for example, to try to cut down on smoking. We help pay back student loans in order to get people to take up teaching. But most of us wouldn't criticize someone for becoming a teacher, saying they're taking advantage of a loophole in student loan agreements.
I can't see a principled way to draw a line in this, other than to simply accept laws for what they are, and similarly accept those who conform to the law as "law-abiding".