Well this sort of thing especially is where MATLAB shines (i.e. Matrix processing, Signal Analysis, hence MATrix LABaratory), especially with 3D FFTs like you'd

Well this sort of thing especially is where MATLAB shines (i.e. Matrix processing, Signal Analysis, hence MATrix LABaratory), especially with 3D FFTs like you'd do with fMRIs. So that's fine, but once you start getting into Monte Carlo simulations and massive batch processing, event filtering, instrument calibration, and all your database connections and all sorts of other stuff, it honestly just doesn't scale up or provide a complete solution. So you end up doing some in MATLAB, some in C, some bash scripts, some in whatever else. Python gives the flexibility at all stages to solve all that in one or two languages (C/C++ for optimization, python for everything else). I do know chemists that use MATLAB, but not the computational chemists on the big clusters. Most the solid state physicists I know use OriginLab, LabView and even Maple or Mathematica all on Windows and proprietary stuff like that, usually because they are hooking up to various instruments. Even R has been more popular with the physicists I know than MATLAB. Maybe this is all just a big anecdote, but I also work in scientific computing as well, and this has been my experience.