The local writers group had Jeff Mackowiak as a speaker/judge. Amongst his academic interests is "badness in poetry". I didn't attend the meeting but maybe I should have. I read small-press literary magazines, online writing forums and go to writers meetings. Not all that I read or see at those venues is publishable. Bad or not, I think there's much to be learnt from it. Equally I think one can sometimes learn much about a well-known writer by considering their less successful works, where their techniques, quirks and habits are sometimes laid bare.
Reading anonymous work is a useful exercise - sometimes only the author's name distinguishes "pretentious" from "ambitious". Those who only read good work are leaving themselves vulnerable to charlatans, or to people who can imitate what sells. Bad work gives you a better appreciation of what is easy and hard to do, and helps you to calibrate your appreciation of supposedly better works. Bad work might be excellent in some respects - plot for example - but fatally flawed in another. It may be patchy - should a work be judged by its worst passages or its best? In "Reading like a writer" Francine Prose notes that "At lazy moments, F.Scott Fitzgerald could resort to strings of clichés".
Work in student magazines or contemporary foreign magazines can be especially useful - it might be brilliant, it may resemble nothing that you've read before. You can't judge by looking at the author's name. Sometimes even the genre is unrecognisable. You're on your own.