He's absolutely right about the fact that performance is important, but my issue with his argument is that he blames individual developers for not caring about performance. The problem isn't with developers themselves, it's with the fact that they aren't incentivized to care. If companies feel that performance is important, they will budget for it, invest in making their code fast and invest in their people so that they know how to do it and reward people for doing so.
If they don't care, a developer has to go out of their way to do incredibly time consuming and difficult work for practically no reward. Naturally they're going to want to focus on things that will help them in their careers. Going above and beyond constantly when your employer doesn't care, or even worse going against your employer is a recipe for burnout.