Grant me the serenity to accept the things I cannot change, courage to change the things I can, and wisdom to know the difference.

It's not about right or wrong. I'm not in that judgmental frame.

You don't profit from seeing the glass as half-empty. If you resent other people for being "robots" you are wasting your cognitive energy. 

The label "average" has less inherent resentment.

A binary way to categorise people doesn't allow you well to see how they really are. Most people take some responsibility for some areas of their life but don't take responsibility for others. 

I have a friend who takes much responsibility for his life. He lives in Germany. At the moment he's stranded in Canada. Someone stole his briefcase with the flight tickets to return back to Germany. As a result he has to stay a few weeks in Canada without any money. 

You can have a trusting relationship with your hairdresser without needing them to have big dreams about their lifes. 

That relationship doesn't fullfil my need for intelletucal stimulation, but that's fine. It doesn't make him a bad person and I can still be nice to him.

There are lots of people with whom we interact where we profit from having a good relationship with them but who are average people.If you think of them as robots it makes it harder to interact with them.

Joshua Foer in "Moonwalking with Einstein", however, doubts about his self-proclaimed autistic disorder, and he says that Tammett looks like a totally normal person

Socializing is a skill that some people with autism can learn. I know someone whom I judged the first time I meet him as autist based on mode language before he opened his mouth. I later heared that he's clincially diagnosed. That person is now one of the people I now personally with one of the most impressive social skills I know. 

Tammett facial expressions don't look "normal" to me on the videos I saw (I never meet him in person). I don't see the emotions in his face that a "normal" person has. 

As far as Tammett goes, his way of teaching "native" math suggest that he doesn't deal with numbers in any normal way. The mindset that he demostrates in his books also looks very "unnormal".

The core question is:"If memorization techniques are so good, why don't make more students become top students by using them?"

As far as the story about Tammet goes, you forget a few elements. Tammet did use some memorization techniques but they weren't all of it.

Tammet is a born autistic savant and no example of what someone with a normal brain does.

The time he was tested on his knowledge of Icelandic was immedietly after the week of practice, before he had time to forget something about it. Most people who want to learn a language want to keep the skill. Keeping a skill means that you have to continue to spend time with it.

In pickup the equivalent of practicing speed reading or doing memorization exercises is to practice approaching. There are even a bunch of specific approach exercises that you can do that are just practice and don't exist to produce direct results. 

You won't get any skill in any of the three categories by spending much time with digesting theory.