It seems like you are thinking that miners are in charge of Bitcoin and decide its rules and maybe even can do whatever they want with the network, right? This is a very common misunderstanding, Bitcoin has a pretty complex balance of powers, and miners are only a one part of it. First, you should know that miners can only create new blocks that are later validated by every participant of the network - they can't change the rules or spend someone's coins without signatures. So, every user who runs a full node also has a "vote" in Bitcoin's protocol, because the network nodes is one of the elements that makes Bitcoin decentralized and valuable. Also, miners are simply following the most profitable coin, so wealth in a form of cryptocurrency or fiat can be used to create incentives for miner - miners are not attacking or abandoning Bitcoin even if they really want to, because it's more profitable to be honest. And developers are also playing big role in consensus - Bitcoin is valuable because it has the best cryptocurrency developers in the world, so when miners try to create an altcoin, like they did with Bcash, most people don't take it seriously because it is developed by unknown people without any track record.