I disagree. Cryptographically strong random numbers take a lot more CPU time to compute
(assuming you don't have a HW accelerator). Since the vast majority of C programs don't need
strong random numbers anyway, why should we waste all that energy?
In addition, creating strong random numbers is hard! The proper algorithm strongly depends on
the problem you're trying to solve. The libc developers can't possibly know why you want
these numbers so they punted. And I think they were right. Anyone who believes that there is
a one-size-fits-all PRNG algorithm has never tried to write one. :)