I suspect you only choose folksong as the comparison because the two environments are tolerant of abuse. Poetry, and it's bastard sibling "storytelling", share with the folk music movement that huge failing of taking contributors at face value, at least to start with. That tolerance is used by the boring, needy, unsympathetic, deranged and self- obsessed as a free pass to inflict their unconsidered compositions on those who in politeness will not leave the room.

I've had it put to me that the Meejah and that lot find sincerity problematic. Hence thir problems with morris dancers and train spotters. So the question only remains, why does that shower accept sincere poets but not sincere songwriters?

Simples, as the saying apparently goes. The Meejistas think they could write poetry if they could find time in their busy schedules; but they'd never find the time to put it to music.