It’s easy to kill a dream. All you have to do is tell someone it’s not possible. That it’s not worth it. That they are wasting their time.
To some, that will kill it immediately. Others need to hear it a few times. And some have the instinct to persevere in the face of doubt, clutching to something they know has hope.
If a dream will be killed, why not let someone else do it?
Instead of making a judgement, ask an open ended question. Who knows what will come of it.