In financial modeling, which is one of the primary applications of MATLAB, you generally throw away your code in 1-2 years anyway (unless it is a generic library that can exist for decades).

MATLAB is a tool for research, not engineering. In research, you check hypotheses; you write a lot of throwaway code. The 0.1% of validated models that end up in production can be rewritten in other languages, but nothing replaces the fast turnaround time of MATLAB. Or similarly organized R Studio.