If I cannot understand your writing, I'm not a stupid reader. You're a crappy writer. As the communicator, your audience is always right. If your audience did not understand you, then you've not done your job. It doesn't matter how ingenious your writing is.
To authors who constantly warn readers not to plagiarize your writing: Don’t flatter yourselves. What makes you think that your writing is worth copying from? Not that I support plagiarism, but it’s not like you can take any legal actions against the offenders. Kick them of fictionpress while they just sign up for new pennames? In the U.S., every original "literary, dramatic, musical, artistic, and certain other intellectual works" is copyrighted once it’s in tangible form, but you can’t sue for damage unless you’ve registered with some federal department for an official copyright. If someone plagiarized my writing, I’d be like flattered. Then I’ll be pissed. But I’ll suck it up.
Common complaint: “If you don’t like my story, then don’t read it.”
My interpretations of fictionpress’s rating system: (I’m generalizing and don’t mind if you proved me wrong.)
M: Stories with a plot and promise of intelligent content written by NON-grammatically and NON-vocabularically challenged authors. A category where most decent stories are found. Unfortunately crap written by tweeners/teeners who use excessive profanity, suicidal themes, or explicit content also fall under this genre.