When I started in 1991 there was only one agency in LA county that issued every officer a 1911 .45 ACP, that was El Monte PD. (West Covina PD issued H&K P7 M-13 squeeze-cockers, $$!!) Many agencies allowed individuals to carry the 1911, but EMPD was the only issued-carry one. I will assume that the 1911 manual of arms, the limited training, a serious potential for apathy/complacency with some officers and maybe even the image of cocked pistols riding in holsters had something to do with Chiefs not issuing them or saying no to their people carrying them. Ya gotta remember that most police chiefs are appointed to at-will positions, they can get canned by either a city manager or by a council vote with or without cause at any time with little notice. Sheriff's are usually elected, so bad press can hurt them at election time, too. When someone's income stream, health care benefits and future retirement are tethered to a political body, those people tend to become political animals for survival.
The only ND I dealt with in as a field Sgt. at my former agency was when a SWAT ofc. working on my patrol shift with a 1911 went to a burglary-in-progress call in a condo complex. He stepped through a brick-shattered patio sliding door to go into the condo, as as he did so the remaining glass from overhead let go and landed all over his head/neck. He tightened up (A startle reflex I guess?) and sent a round down through the baseboard of a living room wall. I will assume that the same thing may have happened with a DA/SA or a striker gun in the same situation, but it didn't. The Chief, Captain and many of the Lt's at the time weren't gun-savvy people, so when this incident report went up the chain the Chief wasn't happy at all. All1911's were soon ixnayed from patrol use and then SWAT lost them shortly after.
My current office will allow a 1911 to be carried if it's a quality firearm and the person qualifies with it. The last 1911 a guy bought for duty was a really sweet STI.
I guess it wasn't broken in or fired enough to ensure reliability before he brought it in for qualifying. It jammed so many times with 230 gr FMJ with each mag (he had 4!) I failed it.
Sadly, the guy who plunked down North of two thousand for the STI went home with an issued Glock 19.
Stay safe.