I think as the military becomes increasingly reliant on technology and information systems an even stronger argument can be made. If you have a seriously competent Steve Jobs or Bill Gates type computer nerd who wants to serve and is very capable of making contributions in that area, give them the opportunity to do so. Knowing that the sons of America were about to storm a beach, I would want exactly such a person hacking and degrading an enemy's defensive systems. I would not want such a person leading them on the ground.
The Billy Gates analogy was great. Why would the Army drum someone like him out just because he can't call cadence for a platoon of basic trainees? Makes no sense...