the only reason I can think of is that its fun destroying things. Persinaly I rather blow up a house then building one.
Only because you've never built a house before.
See, when you're young you like to break things, because you view it as an excercise in power. (To destroy a thing is to control a thing). You lack the power to create something equally complex, so instead you destroy it.
As you get older, and more knowledgable, you realize you can actually make something that complex.
Which is why pretty much all people who are hackers/virus writers are between like 13 and 25. After that you learn that it's a better show of prowess to create than to destroy.