Oddly enough, PLCs are another example of a dataflow programming being intuitive for regular people -- the others being LabVIEW and Excel. Of course I'm exaggerating a bit by putting all 3 of these tools into a single category, but I also don't think it's outrageous to make this claim.

Indeed, PLC's originated with GM calling for a programmable controller that could be used without having to completely re-train their large workforce of control engineers and technicians, who were already familiar with relays, mechanical timers, switches, and so forth.