I think a big part of the issue is that soldiers and people in general as George mentions above have fears.
Moving left or right of their current "center" or what is familiar to most people is can be a very scary thing. We don't have much security, but what we do have, we want to hold onto.
People create all sorts of coping mechanisms to deal with things. Programs like battlemind try to work as close to that "center" as possible to allow people to open up and trust.
Trust is the big issue.
So, you take a "eastern" practice like aikido, were we use a different language, we kneel, bow, oh yea...we wear pajamas and many of us wear "dresses" and you are far, far to the left in what most ordinary people are comfortable with.
I found it better to embrace and exploit the "center" line and to look at what I could personally do within programs or areas that soldiers are already familiar with.
Really when you get down to it, the Army Combatives Program allows us to reach down and accomplish many of the things that Aikido is designed to do. Maybe not as literal or directly, but at the base...it is a practice of budo for those that decide to participate on an ongoing basis.
Sure, you get a bunch of young studs out there that are quick, agile, and strong and they certainly figure out how to use those skills successfully to beat their opponent. However, many of them find out that they are not so successful with those same skillsets against a 44 year old, liberal vegetarian!
AND they decide to explore the practice a little deeper to get better.
That is when we start looking hard at posture, relaxation, breath, timing etc.
It is not for everyone, but for the ones that take to it, I think it is a good thing as you guys already know!