That might be case for small non-modular PLCs that replace what would otherwise be half a cabinet worth of relay rat's nest. That is a valid use for PLCs and th

That might be case for small non-modular PLCs that replace what would otherwise be half a cabinet worth of relay rat's nest. That is a valid use for PLCs and the ladder diagram is also somewhat natural for that. But in many cases you have large-ish systems that have various lookup tables in PLC memory, do non-cyclical communication (ie. communicate with something external over some “normal” protocol, not over fieldbus) or even just contain many instances of the same logic (there are PLC families that cannot do indirect accesses to the process image memory, so if you want the PLC to do 12 instances of the same trivial logic, there is no way to do that in a loop and you have to copy-paste that 12 times…). In my opinion for many of these situations just programming the thing in “real” programming language (even while preserving the cyclic process image model) would be very beneficial.