I'll admit that an unadorned two-wheeler doesn't make much sense for anything but rushing paperwork around. I'd expect the Newsboys to be equipped with a rack at the least, but the LGs and the three-wheelers make more sense for industrial use. The three-wheelers would be a natural for factory maintenance.

I think they're all overbuilt because they'll be used by uncaring individuals, given little attention and maybe even some deliberate abuse. I can picture a factory worker snarling about having to pedal while the bosses breeze by on electric golf carts.
"Wow, how'd that frame get bent?"
"I don't know; it was like that when I found it."
"Right. Well, I'm not gonna say anything, but here, put your foot up against it here and pull there while I hold it ... a little more ... okay, that looks good enough."

Worksman doesn't say, but I suspect that these are built of fairly soft low-carbon steel. It needs to be a fraction thicker for strength, but it's cheaper and has the advantage that it will deform more without cracking--and can be bent back into shape. This will give the buyer's rolling stock a little more longevity so it can be expensed off.