From my opinion if you think he doesn't deserve the job because of his stutter that's too bad. I'm almost a 100% he chose the field he is in and wants to go full time because he thinks he can do it. Asking him to get better at presenting is acceptable. Asking him to speak more fluent is too much to expect and in my opinion not nice. I don't think I'm being very outspoken to say that we can't do public talks or that we shouldn't. I think the world needs to get in the place of just accepting that people with stutters exist and that we should be accepted for the way we talk and the way we speak needs to be normalized.