Really it is ignorance. The opportunity cost for griefing is very high, even if you take cost related to getting kicked/banned/permbanned. People who grief just don't realize that if they spent half the time actually getting/making stuff the normal way it would take half the effort for the same results. It takes a lot of energy to travel out to a wilderness outpost, risk getting killed by mobs on the way in and back, falling in one of those death holes that surround the spawn, plus the effort of marketing/selling stolen goods. It just isn't worth it in time and in rupees when you could get/make the same stuff in legit fashion without any of the other headaches.
Possibly because it's seen as such a bad thing in the minecraft community (for good reason), if you want to be a real jerk to everyone, just break stuff.
