From a technical perspective, this is bullshit, bullshit, bullshit.
But this is a UX question. I could see there being unintuitive nonlinearities with how a user responds to load times. Coffee, too, can be very important to user experience. I'll allow it :)
Yes, with waiting time there seem to be a zone of frustration. Waiting a short time isn't a problem. Waiting a long time, i.e., 8 minutes gives me ample time to do something else,like, getting a coffee. However, a waiting time in between is frustrating as I am waiting wasting my time, and I know it.
But this is a UX question. I could see there being unintuitive nonlinearities with how a user responds to load times. Coffee, too, can be very important to user experience. I'll allow it :)