Here's the true culprit.
Don't blame Cover or VShojo or even Kson herself. Blame Melody. This little skank spreads a mood-altering STI that eventually turns everyone it infects into VShojo acolytes. I wouldn't be surprised if Bao is announced next...
Basically if you want to keep your oshi free of the taint of VShojo, keep them away from Projekt Melody.