"They say I should keep my system secure and up to date, but why? If these people just stopped hacking my computer I wouldn't have to worry about it being secure and up to date. So why should I bother updating it, I have the right not to"

Your prof is living in fantasy land ,with candy cane trees and chocolate dogs. Some people are good, some people can be bad and kids can be little bastards(i was one). That is just the way it is and it will always be forever and ever and really, what fun would life and the world be if everyone was perfect. Its kind nice though that such naivetiey still exists in anyone over the age of 6.