Sounds like M. Perloff has been reading my blog (he flatters himself).
Perloff & Latta are both right to some extent. Sure, as JL says, there is culture & poetic material everywhere, let's not be backward, stodgy & elitist. Then again, it would be nice, it seems to me, if poets took a sharper interest in the purely literary & poetic effects & origins of their metier. "Language" is indeed everywhere... but not always real solid intense true poetry.