@starshaped weird! I wonder if there was a "class" thing involved, not that my house is anything fancy, but they used to do this with flooring material too
the "public" rooms in my home have oak hardwood flooring and the non-public rooms (ie bedrooms) have Douglas fir wood flooring
that was a cost thing, and it is a kit house (craftsman) so I know it is original, it runs the length of the house under the walls, and they'd choose to just put the spendy stuff where most people would see it