It also seems to have a very simple drag & drop interface where you can combine input sources via logic gates to output sources, including a simulator.
Great, but you can invest the hundreds/thousands of EUR by which Arduino is cheaper in having someone do the coding/setup, no?
It is just a matter of where it is acceptable or not. If one hour of downtime will cost 100 of LOGOs, production managers won't take a risk with an Arduino not rugged.
Arduino is definitely not cheaper. I've installed and programmed several LOGOs, and it's easy as hell. It's a compact package that already contains, in itself, enough inputs and output that can be used by i.e. electricians. An Arduino requires you to take the soldering iron into the hand.