First glance at a book noted by Anastasios over here : Stephen Cushman's Fictions of Form in American Poetry. Cushman hypothesizes (in the epilogue) that maybe poets & poetry aren't taken very seriously in America, not because Americans are (stereotypically) vulgar & materialistic & philistine, but rather because they take words so seriously (a revolution & a constitution being the founding events, rather than an endless stream of time & traditions). Poets are kept at arm's length because at some level Americans sense that the poet's words might shake things up.

Sounds like a stretch to me, but maybe there's something to it...