&gt; Why isn&#x27;t Haskell, or any other functional language, popular for this sort of thing?<p>Because some of the scientists doing this are bellow average programmers. Look at the author singing praises to Python while benefiting from C, Fortran and Cython. He doesn&#x27;t understand that what actually matters is what&#x27;s under the hood, and you want him to learn functional programming and rewrite his algorithms?