Is there such a thing as a good virus (don't just think of your own body as well, think of ecosystems, symbionts etc)? Couldn't there be some harmful implications of a drug that eliminates ALL viruses?
To compare: There are lots of useful bacteria in your guts, and when you take antibiotics most of them die. But most people survive that, and you can help re-populate your guts with the right mix of microbes.
I'm curious about this as well. For example, during the implantation of a mammal embryo, endogenous retroviruses are produced in large quantities. I don't know if the double-stranded RNA targeted by DRACO is present in that situation, but it's certainly something that would need extensive testing.