First off, miners need to ensure that the coin they're mining retains value, so they need the network effect of the entire economy. No miner is going to make a decision that makes the underlying thing that they are mining worthless.
Even if 80% of miners wanted something, if it was egregious enough, like a change in supply, then no one would go along with it. Ecommerce companies like Coinbase etc would just ignore the fork and keep going with the remaining 20% of miners whose heads are screwed on straight.
Those 80% of rebel miners who are burning all that energy, and have all that sunk cost in hardware, would be stuck mining a nothing coin that no one wants, and would lose everything almost immediately.
Remember, miners have sunk costs. They, more than anyone, need the coin to retain value. Their incentives are incredibly aligned with everyone else in the ecosystem.
Even if 80% of miners wanted something, if it was egregious enough, like a change in supply, then no one would go along with it. Ecommerce companies like Coinbase etc would just ignore the fork and keep going with the remaining 20% of miners whose heads are screwed on straight.
Those 80% of rebel miners who are burning all that energy, and have all that sunk cost in hardware, would be stuck mining a nothing coin that no one wants, and would lose everything almost immediately.
Remember, miners have sunk costs. They, more than anyone, need the coin to retain value. Their incentives are incredibly aligned with everyone else in the ecosystem.