I get what you're saying about price/performance, but only a limited number of people actually do the research when buying graphics cards.
For an example, in a store, you see two cards next to each other, an ASUS Geforce ROG GTX XXX, and an AREZ Radeon XXX, what will you buy, a card from ASUS, a company you've heard of, or AREZ a new name (even though the card, or the cooling itself, is just as good or better?).
If you follow the PC industry, you'll see through the branding and you can make a rational decision and buy whichever has the price/performance, or whatever you're after, regardless of the branding. But if you're just a customer buying a card for that new "gamer" rig, I'm guessing you go for the stuff for "gamers", in this case you get ASUS ROG.