I'm not so sure about "illiterate".
I've had a fair amount of experience of vintage motorcycles over the years and it's nothing unusual to find sub-contracted castings with various generic quirks of this sort - Blackburne-produced engines parts are particularly well-known for it.
It's simple lack of thought, a quality which I'm afraid our grandfathers displayed in abundance at times.
I was reading Roland Huntford's book about Scott a while ago, and there is reference to one of his ships having a number of serious defects; lack of an effective pump, for one thing, and a serious leak caused by over-boring of some through-bolt holes in the keel, which were simply hidden with washers rather than made good.
These were faults which were apparently known at the time, but it was no-one's business to rectify them; the yard simply did what the client specified from his London office, and sent a dangerously flawed ship to take part in a polar expedition lasting years.
''the stopes soared beyond the range of our caplamps' - David Bick...... How times change .... oh, I don't know, I've still got a lamp like that.