Because they want to mine until the last second, supposedly there will be a lot less ETH being generated after the merge so each one will be worth more.
> supposedly there will be a lot less ETH being generated after the merge so each one will be worth more
This has been hands-down the most ignorant view of the ETH-merge proponents. The floor of the currency is tied to the cost to mine. There's minimal cost to mine now. The price will fall. It's not a supply vs demand problem.
> The floor of the currency is tied to the cost to mine.
This is not true because of difficulty adjustment. If the price drops enough so miners are losing money, some of them quit, the difficulty adjusts downward, and the economics improve for the remaining miners.