\"Shock tactics\" can be a very effective way to provoke thought and discussion among people who would otherwise not look at art (or at least not look at art in any further way than purely judging its aesthetical value). If you have something important to say you might want to reach those who aren\'t already on your \"side\". To get them to bother you must find a way to MAKE them bother. It might seem like an arrogant tactic, but in the end people chose if they want to bother or not. Funny thing is, people ALWAYS seem to chose TO bother. 
Also, I find it important to remind people about the darker sides of humanity and our history, as we have an unfortunate tendency to forget and make the same mistakes over and over again. We also have a problem of thinking \"outside the box\" and seeing how some phenomenons can have effects on very different levels (some of which not that obvious). I\'m not saying that artists have all this information that the rest of us lack, but by challenging ones values and opinions they can make people think in new ways, and at least I find that useful.
Also, I find it important to remind people about the darker sides of humanity and our history, as we have an unfortunate tendency to forget and make the same mistakes over and over again. We also have a problem of thinking \"outside the box\" and seeing how some phenomenons can have effects on very different levels (some of which not that obvious). I\'m not saying that artists have all this information that the rest of us lack, but by challenging ones values and opinions they can make people think in new ways, and at least I find that useful.