to all but hidebound prescriptivists.

By saying this, you attempt to silence all those who might disagree with you, perhaps not realising that those who disagree with you, might also reject such a qualifier. I don't consider myself a hidebound prescriptivist - I'm more of a fundamentalist egalitarian, if'n I'm going to apply any label to myself at all - but I DO consider that middle example to be wretched and unpleasing to the eye and ear. And just plain WRONG.

But then, I also believe that verbs has to agree with their subjects.