Using '--help' for aliases

Hello all,

I am yet another user of 'git alias' (who wouldn't ?). It has become so natural to me to use the aliased version that at some point of time I tried the following,

That made me wonder. Git is able to inform the user that 'co' is aliased to 'checkout' but isn't it possible for it to take one step more to display help ? Just wondering if there were any reason for not doing it.