The miners are the big deciders in Bitcoin. They make most of the money, and the ones who ultimately make the decision on what new code gets accepted. They join their miners to the mining pools who support the policy they want. The miners want to make money forever. They want their coinbase...
To be fair the USD is doing really, really well. Since everything is traded against the USD that makes everything seem like it's doing shit. Obviously, currencies have ups and downs but since there is no limit to the how many USD can be created, inflation is inevitable.
Ethereum is a rising star of the cryptocurrency world. Closing in on the original digital currency bitcoin, it has swiftly become the second most valuable of the new payment methods.