Writing and drawing to me are achievements I am proud of (even with the constant nagging at the back of my mind, "could be better, there's problems with this and that, and..."), so having to pretend I don't do these things would be emotionally crippling.
Plus, keeping track of who knows what, and who may not be told what, sounds like enormous effort.
EDITED TO ADD: Mind, I understand and completely agree with the concern regarding crossposting comments on friendslocked entries. That it was made possible makes no sense whatsoever.