The word "vinegar" is notably absent from that link. That solely shows that harsh soaps are harsh (which as you may have noticed is axiomatic), not that vinegar isn't.
When I typed the word "may" I meant it. If it's medically established that properly diluted vinegar dries the skin I'd be interested in knowing that. Otherwise, it seems like reasonable speculation to me rather than pseudo-scientific BS.
>notably absent
Maybe that's because vinegar isn't a staple in the hair care aisle at Walgreen's.