They didn't want to hear "Puff the Magic Dragon?"
Sometimes tour promoters book opening bands that don't make sense. The Eagles of Death Metal opened for Guns N' Roses and they are not metal. Axl Roses insulted them after the first show and they were kicked off the tour.
Remember the Blues Brothers, when they get booked to a play a country bar, so they have to change what they play?
That happened in real life when The Cure played a metal club. They were forced to play 10:15 on a Saturday Night over and over again, because that was all the metalheads liked.