Yeah, I've given guitars away. One, playable, went to a charity shop a while back, and a good few years ago I gave the remains of my first guitar to a young guy I knew who fancied trying to do it up.
EDIT: Spot the dick!! (Me :roll:) I thought "I forgot to vote..." and promptly clicked the wrong button :lol:
But then I realised it was the right button for me :lol:
In answer to the question - yeah of course it can be "right" to throw a guitar away, assuming it's yours, of course!