I find certain people to be have similarities to small insect pests, such as the common house hold nuisances like cockroaches.
They may be small, insignificant even to larger more damaging vermin like rats to perishable goods in ones home. And the overall longevity to ones health more than different possibly life threatening disease ridden vermin.
But if you leave cockroaches unchecked for too long, they fester to larger groups. Procreate more tiny disease ridden creatures. I suppose in some cases, quantity can be even worse than quality.