Right...
AMD also don't sell cards, they sell chip's, AIB's put those chips on to PCB's and turn them in to cards.
I can see why for example Sapphire might like to make more Nitro+ cards than Pulse cards, its the same reason retailers will want the same, it doesn't make any difference to AMD, they sell Sapphire 10,000 chips at a time for a set price, its up to Sapphire what they do with those chips.
Its another one of those things where its easy to blame AMD because all AMD will say is "we encourage MSRP" they are never going to say "its because retailer / AIB's don't want to make or sell MSRP cards when they know they can sell every over priced high end card they make"
AIB's / retailers also aren't pushing the blame on AMD, what they are doing is wording it in a way that makes it appear like its out of their control and because someone needs to take the blame for it it ends up being the one that can't really say anything.