I don't know. Live and let live comes to mind. If he's scaring off newcomers, it's unfortunate, but maybe they weren't ready. A lot of people and their behaviour frightened and appalled me when I first got sober, but I wanted and needed to be there, so I stuck it out.
There are people in meetings today whose sobriety I do not admire. I do not like their conduct at meetings. But just because they have been sober x amount of years doesn't mean they are healthy people.
Taking this guy on in an attempt to change him will likely blow up in your face. As corny as it sounds, I think you should pray for this guy. Pray until you don't feel this way toward him anymore. Keep working with newcomers, and keep the discussion on recovery, and OFF the troublemaker.
And above all, lead by example. By being respectful of others inside and out of meetings goes a long way.