There are so many variants on hackers. Some want everything to be free and thus leech forever off p2p networks. Some want everything to be free and so spend hours writing linux code. Some are bored and marginalised so write viruses to get back at the world that owes them one. Some are bored and egotistical and so do the same. Some are insecure and so skiddie hack their friends computers to see what everyone really thinks of them, then those friends find out and bloody kick their ass. Some think that government is wrong and go try and "stick it to the man".

I would say most of the above have some defined mental condition that needs treating.

Some are just curious and want to know what is on other peoples computers. Some want to test/improve their skills. Some want to mount their stolen copy of windows on the wall the way "real men" mount stuffed animal heads.