I remember a study that said people read based on shapes of words, particularly ascenders, descenders and edges (i.e., first and last letters). Does capitalizing the first letter of the sentence make a difference? If it does, do people that read languages like German which has more capitalization (but the same script) adapt to it?
No, you're missing the point.
Naggum didn't eschew all capital letters, only where they led to loss of information (ie. failure to separate common and proper nouns).
Emacs and Lisp are proper nouns and therefore capitalized. Common nouns that happen to start a sentence are not.
It freakes out my wetware text parser to have two spaces before punctuation and no capitalization at the beginning of sentences. At least he did not put punctuation inside quotes...
I personally have no problem with reading text written in a such way.