I guess some time someone will realize routers are both hardware, and software, and shock horror both, if done well, can actually add value. [hint & example: compare the scheduler on, say, Linux/FreeBSD, Windows 95 (sic), and your favourite router OS (*); pay particular attention to suitability for running realtime, or near realtime tasks, where such tasks may occasionally crash or overrun their expected timeslice; note how the best OS amongst the bunch for this aint exactly great].
(*) results may vary according to personal choice here.
Don't use a non-realtime OS for something that you expect realtime or near-realtime OS functionality. There are specific systems to address these kinds of needs with rather complicated scheduling mechanism to accomodate such requirements in a sensible manner. Is IOS a realtime operating system? No. Are any of the other listed OS realtime operating systems? No. (The (*) doesn't count). Do I wish some of these clowns would use sophisticated realtime OS? Yes. Will it solve world hunger? Decidedly not. Cheers, Chris