User blog comment:The Lie is a Cake/Would a (public) party system for PvP work in League?/@comment-8468980-20130530212528

This idea has been brought up before and the biggest problem with it is that it cements in players' minds that solo top, solo mid, jungler, duo bot is the only laning assignment set up we can follow.

In addition, what about picking non-conforming champs for your tagged role? Nasus was never picked for jungler until he became a great jungler pick.