You might be right in cad and eda, but there's surely a case to be made that python libs(numpy, sympy), sage, r, octave could be better that matlab or mathematica.
The biggest thing Matlab has is the GUI (which is surprisingly good!), the documentation (excellent), and the plot viewer. The plot viewer is probably its killer feature. There's just nothing remotely as good in any other software, at least as far as I could find.
Octave's is terrible. Barely any features and incredibly slow.