I suspect there will be reblogs about how obvious the plural is to some speakers, but the point was that linguists—people who parse and analyze fine variations of language—lose grasp of what constitutes a grammatical/acceptable utterance. Consequently, it is not uncommon for us to solicit judgments from people for things that are perfectly clear to other speakers.
It is like how when you a say word/sentence over and over until it loses its meaning; this state of detachment from language is a very common one for the linguist, and that was the idea behind the post.
