Which it should, as its mining which helps add more bitcoins to the market.
It does.
Inefficient miners get forced out while the miners with the lowest bottom line continue to survive and make money. That's how it works. It trades equality for efficiency.
Investors and speculators, along with everyone else, dictate the value most of the time. Miners adjust or sell it for what they can at the absolute minimum to keep themselves alive, and if they get it sold, they continue onwards. If it fails to sell, they fall off, difficulty falls are miners get turned off, now it becomes cheaper to mine.
It all works, technically.