I'd rather have a guy in a wheelchair watching my back who is mentally aware, than some of the 9 y/o kids I've played with who's awareness is NULL.
With that said though, inclusiveness should not be solely focused on those who are physically disabled.
I agree that making airsoft inclusive is more difficult than a lot of other activities, however the reasons you've mentioned almost come across like the idea of inclusiveness is to make an even playing field for those with disability. Unfortunately that would never be the case, for example, someone in a wheelchair is nearly always going to be at a disadvantage even on the most inclusive airsoft site. That might make them a less proficient player than the average able bodied person...
Does that mean that sites shouldn't do their best to encourage them to come along and play? Absolutely not. Turning up and playing airsoft, in my opinion, has absolutely nothing to do with your ability to win, it's about getting away from screens and the monotony of every day life and going outside to have fun with your mates!
At the end of the day we're grown men holding toy guns, if someone else (able bodied or otherwise) can enjoy that as much as I do, I say game on!