Although, I agree that anti viruses are largely useless. There is a way of avoiding deleting your system if you suspect you have been compromised. Although, this would require isolation as I talk about fairly regular, and as mentioned above a operating system such as Qubes OS would be able to assure in most cases that a virus is contained to that environment, and not leak out to other instances. You can isolate your network, and various different things as long as your hardware supports virtualization technology. Its not perfect as nothing ever really is, but its the closest you'd get from having a physically isolated computer.