Or their manufacturing was so imprecise that they had to make more than two holes to (most of the time) get at least two that were in the right-enough place and where the screw would actually “grip” the plastic.

I expect, though, that the first batch used all holes and that this was a matter of using excess inventory with too many holes after realizing that they could do with fewer ones.

Interesting with the imprecise manufacturing, haven't thought about it like that (and obviously don't know anything about the mechanical part of manufacturing).

I'm better at judging the electronics/computer design, and there it's obvious to me that they went out of their way to stay cheap.