I have never used a turkey dog and don't know much about it. However, it is legal in some places and is an old time honored tradition with a lot of heritage in those places. No different than using a rifle IMHO. Or a .410... If it's legal, what's the complaint? I'm not in a position to determine the ethics of how another man legally takes his game. Are you?

Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.