I know several “highly intelligent”, “highly degreed” individuals who cannot write coherently without edits.
To be honest there is at least one PhD that I’m not sure can pick out his own clothes in the morning without help.
I SO agree with you. I've known two Ph.D.s, one of whom you could be describing here, and the other who was so full of himself that he signed his correspondence "Dr. [name], Ph.D." (highly improper to use both "Dr." and "Ph.D." in a title).
As a friend says, if breathing weren't involuntary, they'd suffocate.