[cromulent]

I don't think they are engaged in "willful disingenuous bug-eyed goggling".

I think the author is using the term "didn't understand" as in "I don't understand why you use LOC as a measure of a developer's productivity".

Being a little deliberately obtuse can be nicer, less judgmental, and less confrontational way of disagreeing with someone than saying outright "that's a bad way of doing it". And Finns do tend to avoid social confrontations, in my experience.