It's got nothing to do with shooting skill .
It's about physical realities like big or small hands, (I defy any of you "competent marksmen" to shoot a standard NAA derringer well) and personal preference.
This is one area where we will just have to "agree to disagree"....

IMHO, shooting skill has everything to do with it....whether a product of natural ability or just plain time shooting.....or a combination of both.
I do understand what you are saying and I agree that guns are different and fit everyone differently. But, a person who can shoot a 1911 really well,
should be able to transition to a Glock with minimal adjustments. That is what I meant by "competent marksman."
I'll be 49 years old next month, and I've been shooting for 40 of those years....and I can look anyone in the eye and make the statement to the effect that I have never had anyone hand me a gun that I'm unfamiliar with, that inside five or so shots, that I couldn't hit with effectively and continuously. That includes anything from a NAA mini to a Barrett .50 BMG to an HK MP5.
Bob Munden hit a balloon at 200 yards with a NAA....so did Jerry Miculek.... I can't do that.... but, I can hit with it every time at the distance it was intended to be shoot at.