Most people in the speculation forum don't understand anything about Bitcoin mining. The first thing you need to understand is, nobody running a current process node miner actually turns them off no matter what the price does. You're either an ASIC dealer that spent millions on research and design to make it, or some random Joe that paid a big premium for one. Turning them off makes no sense for anyone since Bitcoin is an asymmetric investment. Unless you're mining with crazy expensive electricity, your current generation miner will either pay off eventually, or Bitcoin will go to 0. There's no purpose in turning it off.
While I like your thinking in general, this is a false dichotomy. You're forgetting that miners can and will SELL THEIR HARDWARE. We all know that mining becomes half as profitable overnight when the reward splits. Then likely the price of mining hardware will drop. If the price of mining hardware drops, couldn't the price of coin drop also, despite the decrease in supply? Do we have a good handle on demand? And what percentage of cash for coin exchange is just miners SELLING TO THEMSELVES to keep the price up?
When I look at exchange traffic and charts, it looks like automated trading to me.