What else would make people pay a fee? I do not think alturism would pay for an infrastructure of 300 mio USD and increasing.
What else, is that the miners don't mine if it's not profitable.
Miners not mining does not force people to pay fee. Difficulty would decrease and transactions would confirm again with less miner.
Most would not even notice.
Some would see that security decreases, but will that make them pay more ? Not neccesarily, since their security preference is different.
Some might think it is still sufficient and continue to free ride, and if no longer, then leave for a better chain.
Again, this is a typical "the tragedy of the commons" scenario.
I don't think he's saying that miners won't mine at all, just that they won't mine no-fee transactions. Already with 1MB blocks, most pools limit the number of no-fee transactions. There is a cost to including a transaction in a block for a miner, and there's no economic incentive to do so without fees. No pool operator in their right mind would allow 20MB worth of no-fee transactions into their blocks; that doesn't mean they won't include every TX with a fee large enough to justify its inclusion.