When I say work I meant more in the computational sense (although wall clock time also counts). If port numbers were on a 32 bit address space, using a random p

When I say work I meant more in the computational sense (although wall clock time also counts). If port numbers were on a 32 bit address space, using a random port for your service instead of the standard one would be a strong security benefit, precisely because of the amount of "work" needed to cross that barrier. But no, there's no good way to justify using an outdated system because of the obscurity factor. It's the asymmetry of work that obscurity offers that provides the benefit. If you're making your own life miserable in the process you're doing it wrong.