The reading comprehension section technically isn't full of it like you say.
It measures your ability to read SHORT articles and analyze their content in a short period of time...
A measure of an individual's IQ is not solely dependent on how well you can memorize biological facts or plug-and-chug answers from mathematical equations. It is also dependent on a person's grasp of analytical and comprehensive reading.
I agree, though, that the WHOLE exam should be computerized (and not just the writing section).
The GRE, MCAT, GMAT, etc. are all computerized anyways.