My ArtScroll machzir says that many, (or was it most?) medieval authorities opposed the inclusion of prayer poems or piyutim in the Chazan's repition of the shmona esray. According to ArtScroll, we say them because the counter opinion of the Rama, one of the giants of Judaism, carried the day. I don't know if this is true or not. I have not made a study of the subject. But let's presume for the moment that ArtScroll (for once) has provided accurate facts about Jewish history.
Before the piyutim begin, the chazan announces that we are allowed to include them "Misod Chachamin uNevonin" So which is it? One man, albeit a very great man, as ArtScroll says, or "Chachamin uNevonim"?
[Question sent by Anonymous]