To boldly go...

Descriptivist linguist Geoffrey K. Pullum over at Language Log is feeling a bit put-upon:

I occasionally wonder whether people might be picking up the wrong idea about the descriptive orientation we tend to promote here on Language Log: because we so often point out that edicts defended by conservative usage pundits lack support from either decent writing or common sense, people might imagine that if college papers were graded by a linguist everyone would get an A+, because the instructor would endorse and excuse all their mistakes.

Not at all. We just figure that once 16 people out of your class of 30 have started copying a given mistake, you'll declare it a regional dialect.