Creation is indeed fixed and constant, but the supply of BTC within the exchanges isn't. The new owners of these ASIC boxes will find themselves in an excess of

Creation is indeed fixed and constant, but the supply of BTC within the exchanges isn't. The new owners of these ASIC boxes will find themselves in an excess of supply and they'll quite happily flood the market with this increased supply, or they'll spend the coins at merchants. Contrastingly other miners with inferior machines will find themselves behind the curve with a smaller source of income.