In reference to pistols with barrels shorter than 4.25", Baer commented: "Its just too hard to get those small guns to run 100 percent. Some people can come close, but close isn't good enough for me."
While I can see that for the 1911, I've owned a number of subcompacts with barrels shorter than that and were reliable. M&P 9c, Glock 26, P2000sk, and probably some I'm forgetting.