I myself do not possess an encyclopedic knowledge, nor will you see my fingers flying over the keyboard.
On the other hand, what I have noticed is that my understanding of the basics of coding, i.e. how to mix and match loops, arrays, conditionals, etc has vastly improved over time.
I frequently forget advanced or language specific topics - and I don't really care, since I can easily re-read about them online and refresh myself.
I have worked as an examiner for computer science university students and also as an interviewer for new hires for companies. What I have noticed is that the best candidates are similar - they have a rock solid grasp of the fundamentals of the language, and just twist and turn that knowledge to acquire the results they need.
You yourself have mentioned this - a good developer with an understanding of ORM can easily adapt to whichever framework he is required to use.
This mastery of the basics is what we are trying to assess with TechTestNow. You might notice that none of the questions require in-depth knowledge of the APIs (although that knowledge might help you solve some of them faster, there is always a solution that uses only basic constructs).
The main reason the tests are timed is because, all said and done, a good programmer does need to have a certain coding speed !
Also, in real life, a lot of time is spent not on figuring out how to solve a problem, but rather on figuring out what the problem is in the first place - what do we really need to do ? (and can it be done at all ?). Although the problems given in TechTestNow might seem contrived, they do have the advantage of being unambiguous, so that the programmer can just concentrate on writing a solution.