>And yet we seem to have a party here which thinks "must not be negative" sounds too complicated to their users. Is it that you and I are just lucky, or what?
>
Mike's point about simplicity is valid and he has the data to back it up in this case, so I respect that and in most cases I'd opt for simplicity too.
Simplicity isn't the only objective I have, though.

If simplicity were the key objective then

"You look nice"

would be more valuable than:

"Shall I compare thee to a summer's day?
Thou art more lovely and more temperate"

History has decided that one for us.