I'm a career flight safety guy. I did the safety job with the Army Guard and I've been doing it for over a decade with the USAF. There is a comparison to Bud Holland that you're refusing to see. The difference is leadership intervened this time. Bud kept pushing and pushing because rather than slap his hand, everyone encouraged him or at the very least tolerated it, and over the years it led to the Fairchild mishap. I don't know the crew of the MC-12 in question, but I can tell you from knowing my history and just simple human nature, had leadership treated this lightly and turned a blind eye, there would have been temptation to continue or perhaps push the boundaries more.
You seem to be pretty stubborn, stating things like "there's nothing prohibiting a King Air from doing a roll"...yet the FAA certification and the POH prohibits that maneuver. I'm quite certain that a highly skilled and qualified test pilot could roll a King Air safely. We all know Bob Hoover can roll a twin easily as well. The difference is those maneuvers are done in a controlled environment with a routine that's been vetted and planned. Not on an ad hoc basis over a combat zone with a normal crew compliment.
Those of you that think rolling a King Air just for the hell of it is "ok" need to ask yourself this question...it's been proven that a Boeing 707 can be rolled. It was accomplished by a Boeing demonstration pilot. Chances are, you could probably roll a 737 as well. But how many of you would be fine if your family flew out on a Southwest flight and the captain decided it would be cool to do a roll over DAL on the way out? I'd be pissed...it's called "risk management", and taking risks "just because" is stupid.
As for the FCIF, I don't think this ONE incident drove that. There's been a lot of discussion of aircrew discipline over the past few years following a few recent mishaps. As someone else stated, this was probably the straw that broke the camel's back and leadership felt they needed to get a message through in a very direct manner.
-- Edited to add about "the good old days"...certainly there were many skilled pilots in the past, but you're omitting the fact that the mishap rate was very, very high. Nearly as many people died in routine training as were killed flying combat missions in WWII. Using good decision-making skills and refraining from doing unnecessary maneuvers like rolling a non-aerobatic aircraft has played a role in saving lives and keeping us from bending metal.