Couldn't agree more with this. He can do this too without an MBA too, but technical + MBA can open up tons of doors whether it's through consulting, a chief technical position, or just plain management. There's nothing better on paper than a guy who can communicate both technically as well as with business requirements and help out with business decisions, revenue generation, etc.
Anyway, I don't see why he wants to change. It sounds like he's just afraid. Make him follow his passion and what he wants to do instead of just taking the path of least resistance. If he loves EE or whatever engineering still a lot, get him to be more confident in his abilities and that college isn't going to be easy, but that if he works for it he can do extremely well anyway (as he's doing already it sounds like).
My degree is not engineering, although in most college it would be considered that. I do work as a consultant, and I love the job. I get to sometimes travel around and eat for free while working with other companies on interesting stuff sometimes. Sometimes my day is a ton of meetings figuring out how to help the client make the most money and other times I'm working maybe in a cubicle, or at home. Depends on the project though. Let's say I'm doing some work for Augusta National Golf Course. When I visit them, I'm not going to be in an office all day long. I don't see why so many people care if it's a cubicle or not. I think liking the work is a hell of a lot more important as long as you're working in comfortable conditions. I also work with sales people and some have engineering degrees. They do a lot of interesting work kind of, but also have a lot of fun. I know of sales people who will fly to Vegas if their client is there, client pays for a limo...they go and have a $1000/person dinner for free, go to concerts, go partying with clients, etc. I was just out with one of our sales execs last week and he made me realize his job is about half having fun and going to cool events just to make the company some $$$.
Anyway, I'd ask him where his passion is. Probably most important and it doesn't sound like he wants to go into something that'll put him in the poor house.