openssh unix dev - Sep 2000 - ssh-askpass and ssh/scp: is this behavior intentional?

Okay, I'm asking this again.

As of 2.2.0p1, the *only* program that knows how to invoke ssh-askpass
is ssh-add.  Not ssh itself, nor scp understand how to invoke
ssh-askpass.

This is a direct contrast to ssh-1.2.27, in which all clients know how
to invoke ssh-askpass.

My question: is the limitation that only ssh-add knows how to invoke
ssh-askpass intentional (i.e., a deliberate design decision)?  If so,
why?

If it is *not* intentional, then I am going to patch ssh and scp to
understand how to invoke ssh-askpass, as I routinely have to login to
machines for which I *must* fall back to password authentication.
(Meaning, they will refuse my RSA/DSA key no matter what I do.)

If the limitation *is* intentional, though, I'd like to obtain a
better understanding as to why, before I decide whether I want to
patch ssh and scp anyway.

Thanks,
James