I would say that as a whole, 1911s are more finicky than some other guns because there is much more variation in the 1911.
The further you stray from a full size 1911, the more likely you are to have problems. The lower the quality of your parts, the more likely you are to have problems. The less skilled the labor, the more likely you are to have problems. The more someone has mucked around with the gun before you get it, the more likely you are to have problems.
A basic manufacturing concept is that the less variability there is in your manufacturing process, the more consistent your product will be. With so many manufacturers making so many variations of the 1911 with so much variability in parts quality and labor skill, then, of course, when taken as a whole, 1911s are much more variable than say a Glock or a Sig, and therefore as a whole are more likely to have problems than those brands.
Now, for a good manufacturer, building a 1911 to correct specs, with correct parts, and with skilled labor, then the 1911 will be on par with other guns built with the same attention to detail.
I have owned way to many 1911s over the years of various brands and quality, and I would guess that 15% of them were not 100% reliable out of the box.