Yuggothians are sore losers. When they were forced out of the Solar Possessions during the Third Epiphytical War, the fungal sporehordes of Yuggoth seeded the asteroid belts and other locations with all manner of Nanoeukaryotic monstrosities, many of which lay dormant for decades, even centuries, before sprouting into horrid quasi-life and spreading murder, mayhem and destruction in their wake.
This was in addition to the massive clouds of infection that were spewed into the life-support systems of every habitat, dome and settlement the Yuggothic forces could reach during their withdrawal from Earth and its surrounding environs.
To this day random waves of spontaneous infections arise and spread throughout the asteroid belts and other such places, most of which are little more than nuisances. Occasionally an infection will achieve a form of critical mass, reach a pandemic level and become a real problem, like the various forms of psychokinetic plagues that induce horrifically violent forms of mass telepathy, serial empathy, nihilistic passivity, or worse.
There are still parasitical forms of hyperconscious plague-minds at loose out on the periphery of the burned-out hulks of ancient orbital bastions and mining cosmoplexi.
The Nobles of the Court of the Silver Key, under direct edict of the Pallid Empress Herself have been engaged in a long and bitter struggle to cleanse the human ecologies of the asteroid belts and the Outer System ever since 'winning' the Third Epiphytical War. To this very day fam-trad collectives and nomadic bands of Purifiers, Purgers and Electrolyters prowl the broken and scorched remnants of the once gleaming orbital domains clearing out masses of fungi, spore-cankers, infections and worse.
So the Purge-teams and Scrubbers continue to go in and wage war on the festering, ever-adapting vengeance weapons of the Yuggothians. Many believe that this continuation of the extermination protocol has become far too extravagant and costly, especially now that the Shoggoths are returning.
Perhaps things have deteriorated too far to salvage the orbital domains.
Maybe, just maybe, the Yuggothians have finally won something of a victory after all.
Just don't let the Monitors discern you entertaining such traitorous thoughts...