Bad business ethics.
It's 12:50 pm and the doors are locked. As I got in my car, I saw another lady walk up to the door with food in hand, unlock the door, and then lock it again after she went in.
Right after, another customer knocked on the door asking why they were closed. She told them, "the registers aren't working." The other customer said this is the second time she's tried to shop here, but this is the first time someone came to the door.
If you're not going to be open during normal business hours, the least you could do is put a sign on the door stating such.