What they might mean is serious dandruff… If they mean it in good faith at all.

I have episodes of subcutanious dermatitis that can get extremely sore like around my scalp and nose and hairline if I take too long to moisturize or clean my face with face wash. It’s a tricky balance because if I over moisturize or over clean, I can go back to the same problem.

I find anti dandruff shampoo is a rather effective face wash for myself.

However. That is unrelated to my hair length. Short hair for me makes it easier to get to the scalp. Otherwise, it isn’t an issue.