You've got it reversed. Mining activity will be tied to the exchange rate. Total mining rewards (denominated in BTC) are constant no matter how many miners ther

You've got it reversed. Mining activity will be tied to the exchange rate. Total mining rewards (denominated in BTC) are constant no matter how many miners there are, so the higher the exchange rate, the more people mine as it becomes profitable for them to do so. Mining is a zero sum game.