I can answer one reason why I often leave my purse in a cart, it doesn't have anything really important in it only my checkbook, sunglasses, a notepad and pen. I have my wallet with all credit cards and money in a pocket and my firearm is nearly always in my on-body holster.

It does happen to be a CCW purse, but when I do have to carry in it for whatever reason the strap goes over my shoulder and the only time I am not wearing it is when my husband is guarding it in the car due to me having to go in to the post office or other forbidden to carry place. Usually the first thing I do when I get to a place with a decent lockable bathroom is move the firearm out of the purse and back into my holster that I am always wearing.

As to safety or not, I have chosen to carry only firearms without any sort of manual safety. I do not want that one additional thing to remember before I have to fire if I am ever forced to defend myself. So whether it's a revolver or a semi-auto I get them without any external safety. To me that is safer.

The safety depends on me not on the firearm.