One idea of poetry is that it lifts you out of ordinary perceptions, with the abruptness of Yeats's "cold and rook-delighting heaven," banishing "every casual thought of that and this." It's got to have that shock to it. But people who don't understand poetry think of that as a kind of aery nothingness, an ethereal kind of concern that doesn't touch them. Then again, some poetry does have that ethereality without the shock, so in that case the poetry skeptic is completely correct to be suspicious. "I too dislike it," responds the poet. In other words, most poetry doesn't seem to live up to that. It doesn't fulfill the function of poetry, but remains simply a stand-in, a place-holder, an alibi, a sorry excuse. This also has to exist, because without it there would be no poetry of the other kind either. It could be a way of lowering the bar and making poetry less scary, although more confusing too.
Of course, I would say that ordinary life is also full of such moments. In other words, those moments of revelation do not reveal a supernatural kind of thing, but life itself in all its awesomeness. You can't just reduce poetry to a Billy Collins triviality, just in the name of making it more accessible to people who don't want that encounter with something more jarring.
When I read Spicer again after a long time, I get that frisson once more.