Why? Because relatively few buyers want a true USGI pistol.
What today's 1911 fans want is a big-boy toy. One that's tight and doesn't rattle. One that will shoot into less then 3 inches @ 50 yards, although they can't hit a bull standing sideways @ 5 feet. The more gadgets hung on it the better 'cuz that's what impresses the guys they meet at the local shooting range.
Of course although it's supposed to be a weapon, they want N.M. (National Match) stamped all over it, especially the barrel. If it’s really a N.M. barrel (which is sometimes doubtful) it will have a tight chamber. Unless kept clean the pistol may start having hiccups, sometimes in less then 50 rounds.
Then there's the magazine. Browning designed it to hold 7 rounds, but ever since someone found you could stuff in 8, the lesser number is out. Do anybody ever wonder why Browning stopped at 7? Of course not!
Nope, today the pistol that Browning designed (and which worked, even in the most harsh environments) is obsolete in the eyes of the current generation. Jeff Cooper's advise concerning "everything you need and nothing you don't," is largely ignored.
But all is not lost. A basic version with better sights can be had from several makers, and a bit of lapping will fix
excessive tightness. As 1911Tuner and I both know, an ordinary pistol with the right magazine, correctly fitted extractor, and service pistol chamber dimensions will feed anything you throw at it.
Been there, done that...