It was hyperbole. It's the same deal in your example: if the is a PoW reward outside the currency, the cost of mining on the wrong chain drops.

The PoW must only be useful for the coin you are mining and nothing rise.

Except the miners don't gain value from discovering a protein fit, so they have no incentive to mine the wrong chain.

Even then, as long as the coin value is larger you will have a consensus with the miners to to mine the latest block. Any sidechains will be neglected, which is why this "no value or nothing" attitude doesn't fit a blockchain network.

> Except the miners don't gain value from discovering a protein fit, so they have no incentive to mine the wrong chain.

Well then they are doing useless work too, and the criticism of wasteful mining applies. You gain value from doing useful things.

Protein fit is only useless for the miners, but they have coin rewards on completion, so the work on new blocks isn't useless to them.

You do understand how a blockchain works, right?

You picked protein fit as an example of useful PoW. How can you now claim it's useless?

Useful for cancer researchers, not miners.

I can claim it's useless for miners and useful for researchers because I understand blockchains and proteonomics.

Do you understand either, VMG? Because it's fast becoming apparent otherwise.