Wow, a personal attack based on assumptions.

I just want to say that I'm not a PM and I don't even work in a corporation. I have worked my entire career focusing on performance (learned programming for and during algorithmic contests were every millisecond really matters, made open-source contributions that vastly improved performance, worked in the gaming space where even users care a lot about performance, and working in the analytics space, where I created a high performance, lightweight alternative to some heavy and data demanding alternatives).

I respect your opinion, but my comment was based on experience, knowledge of human behavior and analytics and A/B tests ran on millions of users. I do agree that it might differ from product to product, but in the majority of cases you just get to a point where it is "fast enough", users no longer notice and spending more time on optimizations takes too much effort for the benefits it brings.