Why does riot not have this feature already, I lose many games with trolls which I have come to expect but can we please get it forgiven from elo, its just unfair.

Riot only hits The Button when the servers become unstable and the quality of every game is reduced.

But if you're talking about a voting system in each individual game, that could be highly abused. I would only say that 8/10 of a vote would allow the game to be written off as a ±0 Elo game, but even then, the winning team would probably not want to vote for it.