The One For All Problem

You see, there are 2 champions on one for all that are permabanned by the system. These are Teemo, and Karthus. While i understand how frustrating 5 teemos and their mine fields of death can be, or how bad it is to respawn just to get ulted back to death by 5 kharthuses, by this logic there should be mutch more champs who are permabanned. 5 teemos or karthuses are not nearly as frustating as 10 shacos for example, and they are mutch more managable than 5 katarinas, 5 zeds, 5 blitzcranks, 5 luxes or 5 illaois and so on. Yet these champs are not permabanned. So i'd like to get these 2 exceptions out of the systems permaban becoulse it's unfair to not let them be played, as well as frustrating for people who actually like playing them. (Yes, custom matches are a thing, but it just takes forever to make an all teemo/karthus team get someone to actually play that game against.)