To be fair (pedantic? devil's advocate?) Samsung ships all their phones with the Samsung store as well. I suspect there's a few other bit names that do similar. A great many Android users have alternative stores, some some probably use them without knowing the difference as well.

To be honest, I doubt many of them care, given all they want is apps from a trusted source, and most people probably trust Samsung if they are buying Samsung phones with specialized Android builds made by Samsung, if they even know the difference.