What happens if he refuses to accept that block, and another miner creates a block without that transaction, and he accepts that. Won't this create a soft fork, and it will be up to other miners to decide which fork to run with.
Have you seen
fork-observer? It shows what happens block forks: it gets ignored. In your scenario, in which certain miners reject a certain
blocktransaction, those miners will need 51% of the hashrate to win this.