No one has suggested that AMD is going to 'change the way they operate because of [bitcoin]'. Before bitcoin, the GPU market was X. Now its X+B. B wasn't there before... now it is. Plus this B market will gobble up 10x of the highest card. This B market has also increased the resale of AMD cards. It'd be silly to flat-out ignore B.
It's pretty easy to ignore the sale of 50,000 cards when you're talking about 6 month sales of 35 million...