Historically one of the first uses for computers was Monte Carlo simulations. In such simulations it's often important to be able to deterministically recreate sequences of "random" numbers. Thus, in almost all computer programming languages, "Random" means deterministic random values. This is a wide convention followed by practically every programming language.

If you want cryptographically secure random numbers, you typically call a function with a different name, one that has "secure" or "crypto" in a name somewhere (e.g., in the function or containing module/package).

This is a convention from the 1950s and has been consistent ever since. That naming-convention ship sailed before many of us were born.