Brains of different people are not in a one to one correspondence, they do not have the same number of cells and even if they had, it is not known if the same information will get encoded in the exact same cell. So some form of calibration on test images/video seems unavoidable. However, in spite of the person to person variation there might be some common ground that allows some level of extrapolation from one person to another.
On a different note, artificial intelligence has always had this PR problem. Whenever it becomes possible to solve a problem that has been labeled AI it appears less impressive, because now we understand how it can be done. This has happened with computer vision, reasoning, chess, now jeopardy. AI is a moving frontier, and consists of things we do not understand well enough, and whenever we do, it is taken out from AI.
Another PR problem has been the difficulty to acknowledge the fact that solving an AI task and replicating how a human does it are different tasks. The former may be approached via the latter but it is not necessary. That said, It would indeed be more impressive and fair if the AI problem solvers (vision, chess, Jeopardy, etc. etc) are solved with systems that consume no more power than what a human brain does.