I can look at porn, and so what? I get some wood?
But trojans and viruses can wipe out my computer, and destroy YEARS of work.
It can destroy a businesses records, databases, customer contact lists, etc.
It can destroy a scientist's research.
It can destroy a student's master's thesis work.
It can destroy a writer's latest work.
And much more.
If they really want to do some good, go after the guys that originate viruses, trojans, and adware.