The point is not that you can set rules, it's that you can prevent other people from changing the rules without your consent, even if they are the majority.

You still have freedom to pick the rules to a small degree though - you choose which blockchain to use. Don't like bitcoin? Try bitcoin cash/ethereum/ethereum classic/litecoin/dogecoin/Monero/siacoin/decred/etc etc.

A common misconception is that miners can pick the rules, but they can't. They can only choose to enforce additional rules (which is powerful), they can't ever violate the original rules.