I don't like the fact that bare-bones no-name brand 1911's go for like $400-500, and in order to be what modern folks call a "usable defense pistol" it needs another $XXX worth of add ons and such. I also don't like how finicky they can be with regards to ammo, malfunctions, etc. But mostly I don't like how everyone seems to think that the Colt 1911 in .45acp can take down an army of bad guys while blowing 8" diameter holes in them, then keep on truckin' for another 1000rounds of mayhem.
It's the same reason I bitch about the AR craze. I own them both, I love them both, but they have their drawbacks. Neither are even CLOSE to being fine firearms in factory as-issued form, but both offer a million possibilities. The fact is, barring nostalgic throw-back plinking, very few today would shoot a 1911 if they were all GI models that couldn't feed HP's and dented the hell outta their brass. Just like they wouldn't a 1960's AR15 that feels like a rattle-trap and shoots 4" groups.
There are, plain and simple, more reliable platforms out there. That being said, you can modify either of the above to your heart's content and have a gun that you'll cherish for a lifetime. Lucky for us, the aftermarket has saved these designs and we can have the great guns we have today. Talk to a 1911 shooter in the 70's, and I assure you he would have cursed that gun more times than he could count.