We haven't specified which exact blockchain we're talking about but in basically all cases you're wrong.
Users just send their transactions to a p2p network. It's miners that pick those up and put transactions into a block and decide which block is the parent to the one they built.
Its the job of miners/validators to pick the head of the chain.
But users have the ability to send transactions to whatever p2p network they want to send it to, even if it's a fork proposed by CurrentB on Hackernews.
I'm sorry that you don't know how either the Bitcoin or Ethereum blockchains work but still have strong opinions about it.
To re-iterate, it's the users (with Full-Node) that decide which chain to follow. That is essentially what a hard-fork is (a portion of these users moving to a different chain) and it requires no special mining capabilities.
Miners follow the users, not the other way around. However, in reality, users are also led by network effects. Users can always cancel any chain the miners have decided to support if they collectively decide to do so.