Likewise, the best music is simple in its core. Starting with melody. If I can't remember the tune, perhaps it was too complex. Apparently it's hard to compose simple melodies. They're like mathematical theories: much easier to appreciate than to discover.
And there is a darker side to complexity. Many in the audience will entertain fantasies about becoming great players themselves and occupying the place of the soloist now on stage. To them, complex technical feats are glamorous and worthy of slavish emulation.