A few observations...
and these are only my views, so...
The spec op guys want 45's because they need something to make up for the putrid M-16, call it what you will.
There is a name recognition factor associated with 9mm's. A "German Luger" is a bad bad piece, as is a "Browning Hi-Power." Not so much with an "EZ 9" (insert your own examples).
As to 9's bouncing off of clothing, that, for me, is right up there with the actual congressional testimony after Waco by ATF/FBI that they used 9mm's "so no one would get hurt," and that, "CS Gas is OK for kids." Yea, really. The problem I read associted with the 9mm by military and poice (FBI) was OVER penatration; rounds ziping right through. Hence the development of the LPJHP-The limmited penatraion jacketed hollow point 9mm. But when it comes to choice, there are many cases where folks in combat zones chose 9's because of the Platform as much as the bullet. In SEA the CIA gun was a Hi-Power. Many in MAC-SOG liked it, and the Sweedish K sub gun as well. Remember that in combat, gaining and maintaining fire superiority is paramount, especially in situations where there is the reallity of ambush and/or folks whose beliefs/motivations we may not ascribe to, but to which we must agree that, at the very least, they believe, and as a result will run right at you while absorbing all of the fire that there is, including air and artillery, so the number of rounds you can put out before stopping to reload is a definite factor. Being able to direct a high volume of fire on a paricular area is a tactic that is employed very effectively.
The likelyhood is that I am going to find a 7.62X39 or a 9mm on an urban battlefield as often, or more so, than anything else.
But hey, you guys are just shootin' the breeze right? Balistics is a science, one that the FBI actually knows something about, and they chose the .40 S&W, so... It's like a computer repair guy I used to know used to tell me when I described the problem I was having. He would say, "It's the cat behind the mouse." And that applies, in my view, with the subject at hand, but lets have some more fun. I'm going to move some of my house plants over in front of my monitor so that they can soak up some of this good free fertilizer. Flapjack.