Because modern ML is a descendant of data science/stats work being done in systems like MATLAB and R. Numpy and scipy were great libraries, and Python was a hig

Because modern ML is a descendant of data science/stats work being done in systems like MATLAB and R. Numpy and scipy were great libraries, and Python was a high-level language that statisticians could use, but also a reasonable enough choice to code a backend for a service in. If the field descended from systems programmers doing high-performance computing, a different language choice would probably have been made, but prior to deep learning becoming popular, compute was not nearly an obvious blocker to improved model performance.