You are asking for Riot to kill off-meta picks, solely because you don't like them? League as a game has managed to keep itself interesting by having its "meta" change throughout the seasons. If Riot were to introduce your idea, they would only restrict meta. Riot have already done an amazing job of balancing the champions in such a way that ranged top laners are not pick-or-ban scenarios.
If someone finds a new lane, roll or build that makes a champ too powerful (e.g. Katarina AD, tank Ekko), Riot are fast to nerf it, so that it is more of a balanced fight, and the champion will have as close to a 50% win-rate as possible. Riot don't want to remove these choices from the player (in fact they encourage it!), there only goal is to make sure that the choices we make between champion type and lane does not lead to an unfair fight.