Robbers are lazy. When they are surprised to see an armed person, they aren’t typically thinking of how to neutralize him and then go ahead and conduct the robbery.
They shrug and rob the business next door.
Some of the “tactical” thinking reminds me of old geezers who can tell you all about burglars “casing” the house. They truly believe the burglars spend several days or weeks studying a house before they break in. In reality, their “casing” is ringing the doorbell. If you answer, they’ll have a reason to be standing there. If not, they break in.
Robbers are just as lazy. They are -not- looking for a fight, they are looking to scare you and make you give them the money.
There is a rash of smash and grab robberies going on in the area around where I live. You are correct. They walk up and ring the bell. If no one answers they kick the door open and grab the nearest stuff. Over in less than two minutes. Security cameras and things like the “ring” doorbell seem to deter them, they just move on.