With all the vulnerabilities we've seen with desktop computers, you'd expect there would have been a major virus that would wipe everyone's hard drive. So far, we haven't seen that, though. Why not?
Because there's no money in it and malware writers are no longer the pimply-faced-youth (PFY) looking to just break things.
No, it's organized crime now. Instead of wiping computers, it's about creating armies of botted computers. It's about bot-herding, and renting out botted computers at literally a nickle a piece (for a limited time only!) for various nefarious tasks. Wiping hard disks is just decapitating the sheep instead of shearing them on a regular basis.
And then there are the drive-encryptors/ransomware that for a fee (in bitcoins, naturally) you can get the other half of the RSA key that encrypted your data when you ran "happy99.exe" or browsed a website with the wrong ad network whilst having a flash vulnerability. Police departments have even run afoul of this.
Attacking gas pumps is useless if you just do denial of service or fuck with volumes randomly with no purpose. However, you'd have to be a complete moron to not see that you can extract money from gas pumps if you can compromise them.