A Permissive ("Descriptive") Dictionary Is a Contradiction in Terms
The same people who say, "I ain't got no use for no grammar nohow" had been using it all along, so they shouldn't be taken seriously. And it's not being used irrationally for unspecified "people," but for one person. So you show that your thinking about number has been affected by this command economy on grammar.
The Illiterate Liberal Language Lords pushed this nonsense on us because it is literally collectivist to treat an individual as plural. But the anti-collectivists blindly use it, too, because they only criticize what their gurus tell them to criticize. The fact that both the Left and the Right media use the same retarded grammar indicates that they are in the same clique.