It could be someone's life work to describe the variations in quality and design across a myriad of manufacturers to describe the '1911'. Folks ignorantly cram the good and the bad, the compact and the full size, the cheap and the expensive, and all manufacturers into one pattern that to them is somehow a "1911". It's as if we could take every polymer pistol ever made anywhere and call it a "17".
That's it, in a nutshell.
I have lost count of the number of different manufacturers of 1911 clones and variants. And even before the 1911 became so popular as to spawn all those versions, there were various manufacturers of 1911 parts.
There is currently only one manufacturer of Glocks.
Therefore, Glock can control the tolerances in all the parts (except for a few aftermarket makers) used to make a Glock. OTOH - with all those various makers of aftermarket 1911 parts and 1911 clones, it would be nearly impossible and highly unlikely to have all of them show working tolerances out of the box. Throw in the modifications that are so popular with end-users and the odds go even lower that they will all work initially or otherwise.
It isn't necessarily a quality of parts issue - so much as a quality of fit and adherence to original specs. The truly amazing thing is even with all that, there are $500 1911's that can and will work perfectly well - and with those that don't, it's usually just a matter of fitting a small part or two (hint - extractor, fps).
So - it could be said that the biggest drawback of the 1911 design is it's popularity.
