> Wow! Not only is the answer correct, but it is also superbly explained. The idea of the bottleneck as the rate limiting step was clearly understood and all calculations were carried out correctly. I don’t see any reasons to take points off from this answer: A+!

I tend to agree. This is exposing a (perhaps universal) bias towards confidence, correct grammar, and a general encyclopedic tone. The trappings of a correct answer, rather than explanatory power and correctness. It’s a con artist.