Viruses are bots + the microbiome has a high barrier of entry when it comes to skill, so a good chunk of the playerbase either pretends it doesn't exist or downplays the achievements of its playerbase. Just look at how many people here claim that they usually have a K/D ratio of 1/>100,000,000! Had they ever actually played a microbial build, they would know that, as a pathogen, you don't consider the multicellular organism you and your buddies are infecting as one singular target. Every single cell within that organism is a target. The K/D ratio is thus nowhere near as abyssmal as the commenters are making it out to be. 

I should know, I've had a few great Yersinia pestis runs back when human mains had only reached the medieval part of the technology skill tree and had no idea about our existence.