I was kicking about Wikipedia yesterday, learning about historical stock market crashes and whatnot, which (if pressed) I could justify as being related to my current research.  Over the course of my random walk down Wiki Street, I eventually happened upon a list of words with disputed usages.  This page claimed that “Some prescriptivists argue not should not conclude a sentence.”  That would mean someone out there thinks that you oughtn’t to say something like (1):

(1) I wish were a rich man, but alas I am not.

Unfortunately, the bane of Wikipedia strikes here; there is no citation for this claim.  I choose to disbelieve.  I’ve looked at a few prescriptivist books, even the ones I count on to mindlessly report every prescriptivist canard the author has ever heard, and none of them make even the scarcest mention of this supposed controversy.  It doesn’t even begin to make any sense.  I know prescriptivists say some dumb things, but I think this is below even their threshold. Has anyone else ever heard this claim, or is Wikipedia — dare I say it? — misinformed?