True enough - hand dimensions are in some ways the deciding factor. But needless to say - a gun has to be made based on that elusive ''Mr Average'' - plus compromize with regard to its intended purpose.
With the R9 we have everything geared to small for pocket - and yet the ability to handle a full 9mm. Quite a feat. Compromize there has meant keeping every aspect as small as possible and yet permit 6+1 capacity.
One of the biggest factors with guns IMO is barrel axis - when it comes to controllability in use- Obviously the lower that axis the better - but then we have to place a trigger where it can be used with ease, plus a grip - and so the compromize begins!
The Mateba self loading revo possibly has the best barrel axis as that is low - about as low as any gun ever got. Almost everything else by default has that axis high enough to make for muzzle flip.
Much appraisal of a gun is subjective - back to hand sizes etc - and strength even in some cases. The Glock grip angle is disliked by some - I am not over keen tho can shoot a Glock well. For others, the 1911 angle is best. Then revo's - well - whole heap of variation there with grip size and angle.Even for me too - grip width - I love the wide double stack feel of my SIG - for others they find it too fat!!
The pup being small is innately IMO very pointable - and being short helps that. Try to point as quick with a 6" barrelled revo - it is not quite so easy I think.
Finally tho - regardless of how right or not the designers have succeeded in a particular example - the ultimate requirement is for the owner/shooter to familiarize - both with feel, balance and, the manual of arms.