The entire concept came from a combat vet and ex-Ranger that was the one time head of the 75th Ranger's close-combat department. He also had access to over 900 actual hand-to-hand after-action reports from Iraq and Afghanistan. So much for it never happens in modern combat. In many of these cases, the troop could have used a knife if he had one he could easily deploy.
Here's a thought... even though there does seem to be a place for close quarter combat in modern warfare, it isn't exactly "common". So why not consult with gangsters, prisoners and assassins? These people see much more blade action than soldiers! Aren't knife designers perhaps barking up the wrong tree?