You actually posted that?
I didn't mean to be sarcastic, but merely concise...
It's actually laughable because what you're debating could also be used back against you because none of those users broke any consensus rules. They could tell you, "For your use case, if you're not willing to pay high fees, then you could use the Lightning Network. It was built for fast transactions and low fees, no"?
¯\_(ツ)_/¯
If you were to suggest the best coin that should be merge-mined by the miners, which coin would that be?
Technically miners should be able to mine multiple merge mined coins at the same time, they don't have to choose only one.
But from a profitability perspective they'll have to check the market and see which coin has a higher value (or is being pumped at the time) that can give them higher fiat reward when sold.
From a utility perspective, the projects have to analyzed individually but if I wanted to choose only one I'd go with RootStock since it is a decent project and I believe side-chains are the better option that can satisfy everyone in this context (ie. provides additional revenue for the miner whilst has additional smart contract capabilities capable of creating
real tokens).
There's also the adoption perspective. If there was a cryptocurrency with the level of adoption/network effects like Dogecoin and its mature market, that would probably be a very good merge mine coin.