Do you see what I see?
“No one ever suggests that they do not understand the meaning of singular they constructions.”
To date, no one has objected to this supposed violation of grammatical propriety. I can only assume that (a) the singular they in this context is so natural and widespread in English that even many sticklers read over it without registering outrage, or (b) the readers who did register it remained silent because they have concluded that I am beyond hope or help.
Actually, both explanations are equally plausible.