The page you link is actually a shortened form and links to the real list: http://wiki.octave.org/FAQ#How_is_Octave_different_from_Matl... which comes in at 2,662 words.
The parts you say are good about Octave are EXACTLY the stuff I use Python and R for. If you want to use a Matlab library or toolkit, maybe cut in paste some code from a paper, do a quick 'what if' thing -- Octave just doesn't cut it.
(My point in speaking up here isn't to diss Octave it's to re-center the reality around Matlab.)
I've used both before. Matlab in my CompSci BS and MS and Octave in my professional career.
I'm just making the point that your critique of Octave seems a little harsh, and to the Leyman skews the reality - that Octave is an open source alternative. Yes, a little rough around the edges if you intend to use the visual aspects of the tool, but for matrix multiplication etc it has its use cases.