Cops, from lowly patrol to SWAT have been carrying cocked and locked 1911's for years and years. There are no safety issues with someone who has the proper training and trigger time on one. In fact it's probably more inherently safe due to the external safety. Its just as easy if not easier to set off a striker fired pistol by accident.
There are a lot of agencies that authorize /issue 1911's for duty use. While it may not have been prevalent in your area, it is in some. From West Coast to East coast. I carried a 1911 as a patrol officer for several years. Went to Glocks due to wanting to carry what my other officers carry magazine /ammo wise. My current department authorizes 1911's, in fact my Chief carries one. I just qualified with my STI and got it approved for duty use.
The "issues" with a 1911/2011 as a duty gun are mainly officer commitment, logistics and cost from my point of view. Yes it is a little more work to master. But that is a individual officer issue. A Officer dedicated to their craft and carrying one will take the time to master their weapons, whether it be a Glock , Sig , Beretta or 1911/2011. When I attended my State Firearms Instructor Class, one of the instructors stood behind me on the line for the first hour of drills, until he saw I was extremely competent with my 1911 and went somewhere else on the line. Not all officers are dedicated to dry firing, training, etc to maintain their essential skills. Those guys wont be interested in carrying a 1911/2011.
An Agency has to maintained certified armorers for the 1911/2011 system, which really isn't that hard or different from maintaining Glock certified armorers. Cost is what I consider the biggest factor. Chiefs used to seeing $300 glocks blanche upon seeing the price tag for a good duty grade 1911/2011. Finding a out of the box duty grade 1911 that's not a full custom house build right now is the bigger issue. For a time the big complaint was changing the recoil spring every 5000 rounds. Sprinco springs are going like 30,000 cycles between changes. Also, depending on the locale/region, it could be 2 years before the agency or Officer gets their pistol back after a OIS.
Safariland has been producing duty grade holsters, level 1-3 for several years for 1911/2011 pistols.