Report system sucks

99.9% of players get banned for saying "%%%" and calling someone a %%%got. Obviously too many bad words for the 12 year olds playing, but why does almost noone get banned for trolling? Is there no way to recognize a troll? Here is my algorithm for the advanced AI it would take: yi has bad score, yi has 6 doran's shields and yi has report --> therefore --> yi troll. Here:
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