Yes, without a doubt.
Negotiating isn't a phony skill. It's a real talent and a big part of the job.
You are talking about developing someone from the board in to a GM. There is no one from this board that could step in right now and do a better job than AA has to date, and AA is a bad GM. With experience and education (some probably just need experience) there are lots of intelligent, personable and motivated people on this board that could be a good MLB GM.
We aren't talking about what people could be or become, we are talking about what they are.
He has a unique skill-set because he has a unique set of experiences. Sure if people on this board actually went for it and got internships and moved up the ladder (which is the point you made in the first place) then yes, they could be better GM's than AA has been to date.