I don't know if the author uses the term intentionally, or as a kind of parody. The "social construct" term has been applied over and over to many phenomena in

I don't know if the author uses the term intentionally, or as a kind of parody. The "social construct" term has been applied over and over to many phenomena in different branches of human knowledge, mostly to produce plenty of confusion resulting from "everything is everything" kind of situation. The humanities are, probably, the most avid user of this term, and that's why the irony. I.e. because we couldn't find a decent definition for what "race", or "ethnicity", or "culture", or "country" etc. is, every such problematic term was labeled a "social construct". So, I think you might be too harsh on the author. I doubt they use "social construct" completely unironically. What they are actually trying to say is that "there's more to branches than meets the eye, and it turns out that it's hard to define what a branch actually is".