Why shouldn't a car stop on an icy road before it smashes into a phone pole even if you put on the brakes, why doesn't E85 work in all cars?
Because machines are influence by outside factors, and some machines are designed only to work properly only under certian conditions.
If you want a handgun that works when limp wristed buy a nice Ruger revolver.
The blame for crap ammo not working in all guns or good ammo not working crap guns lies equally in the ammo as in the weapon. The question should be why can't we expect all Ammo manufactures to make ammo of suficent quality to work in all modern guns. True they are not all designed the same nor do they all feed from the same angle have the same size mag wells the same # mag spring . The answer is because then it wouldn't be cheap and people like cheap alot! Cheap ammo works great in Kel Tecs.......with their very loose tolerances and workmanship that barely qualifies as such. However they go bang, they don't weigh much, and they are cheap. So folks will defend them and blame a quality made ammo for not working in a crappy gun. Others spend big bucks on a weapon and buy 8 buck a box aluminum greasy ammo with varied OAL's and visible grease on them and wonder why they won't work in a gun made for quality, consistant ammo. If you want something to work under all conditions you must give up something else. If you buy something designed sopecifically to work under certian condition and they don't work under others, ones objections are not valid and amounts to no more then whinning. Know what you are buying, expect it to work under the circumstances it is created to work under and do not bad mouth what doesn't work under conditions it is not designed to do so.