Concerning the display: I've seen it quite often at random public places that when a technician tries to fix something on these devices, he or she will connect

Concerning the display: I've seen it quite often at random public places that when a technician tries to fix something on these devices, he or she will connect an external device with display and touch screen (at least when Windows 8+ is used). My guess is that maintenance of such systems is just much cheaper. Virtually everyone knows the Windows GUI.