Edit: Just kidding, I was a few dozen orders of magnitude off, exponents are still quite powerful operators apparently.
However, the real world called and it wants "suboptimal" choices back, for when users don't use good password hygiene.
Also there is a huge difference between (salt + short-random-password) and (long-random-password) because the salt isn't nearly as confidential as the password and knowing it reduces the attack vector to (short-random-password), which is trivial to break for such poor (in this context) hash algorithm.
routers with hard coded passwords in the config don't have users. Device passwords. Often the console/telnet and enable password are the same so there is "a" password.
Of course you could implement as a network admin a psuedosalted standard like our router password shall be prefixed with hostname, "hostnamereallylongcomplicatedpasswordthatsthesameforallhostnames" then rainbow tables will barf because each individual device password begins with a different hostname, even if all of them end with the same "l33tpass0rd" or whatever.
This is assuming you have a sensible hostname strategy, or even assign "real" hostnames to your routers. I suppose people like that who haven't caught up to that newfangled "DNS thing" could use a unique router ip addrs, although now we're assuming a sensible ip allocation scheme and network design. This is kind of reading like Dante, isn't it.