Annoying? A person comes and scans a few of the items on the counter, then leaves again. If that is already annoying to you, you must live a very stressed life
Another related problem is that you physically can't leave the store unless you buy something and get a receipt to scan. You have to tailgate someone with a receipt, or hop the turnstyle, etc. Hope you're not in a wheelchair and change your mind / the store's out of what you were looking for!
Also those stores, at least where I live, have no physical barrier to exit.