The logic is that the guy making the PCB wants to make everything as cheaply as possible, and is liable to leave an unsoldered header row and call it a day. The guy who buys it and wants to connect something to it will have no problem spending a couple of bucks on a plug if it will grab the PCB holes securely and save him doing soldering.
If it becomes a standard then you might see that hole pattern showing up all over the place and you can just throw a plug on it and see what it is...