A VPN per store would be too complex for the vendor so they just expose these to the open.
Same story as with all the hacked OT/SCADA systems in the past. Like those hacks where some SCADA system is open as a website with pump controls.
Imagine they where internet exposed due to simplicity. Imagine you are a store owner with 0 IT knowledge.
The issue is this needs to be handled centrally by the parent org also. They have IT ofc but they usually do POS and desktops/servers. The OT/SCADA systems are usually totally separate and not touched by the white collar IT systems.
2) Yes, obvious it is Russia doing this. Very handy to be able to disrupt food supply and they are also checking our response and time to restore.