I disagree with how he expressed his opinion (doing an attack) about the whole Bitcoin getting centralized but I do agree to some extent that he is right, maybe right now it's not the case but in future the bigger pools will completely take control of the mining operation and then they'll make their own rules and that will again result in a non trustworthy blockchain and maybe these stress test are done by them to increase the miner's fee. I don't think this is how Satoshi envisioned the mining to be, I think it was meant to be completely decentralized and people mining from different parts of the world and not just from few mining farms.
It would have been better if mining would be non-profit in any other any way than just the sheer joy of running your own decentralised mining rig in your basement, as a hobby and as a means to keep the blockchain alive. You could make it break even, so no profit, but no loss, but it is still the market at work here.
I think most things would be better off as non-profit but money makes the world go round not altruism. It really wouldn't be feasible for people to mine for free currently just as it wouldn't be feasible for all doctors and fire fighters around the world to work for free as great as that would be. People need money at the end of the day and most people cant afford to work for free.