In reality, some people in general aren't fit for the work force. Being a disabled vet may or may not have any statistically significant deviation from that norm. Being physically disabled certainly isn't an issue in most desk jobs.
I'm not a vet and, frankly, I'm pretty vehemently anti-military in a political sense, but I've worked with a lot of vets and they almost universally have a great work ethic and an ability to get things done even when they don't want to. From my experience, I'd never think for a second someone's military background, disabled or not, would be a negative.