Scientific computing doesn't (only) mean small tight loops doing linear algebra. Scientific applications can be millions of LOC, with all the attendant problem

Scientific computing doesn't (only) mean small tight loops doing linear algebra. Scientific applications can be millions of LOC, with all the attendant problems of managing complexity at scale. Polymorphism can well be a useful tool to have in the toolbox. Just because it's not an appropriate tool when writing high-performance kernel code, doesn't mean it's not useful elsewhere.