If there needs to be configuration while the system is running, then I prefer SSH or serial console. The images I use on my RPi are configured with an sshd listening on a loopback interface.
My analogy to consumer routers was only to remind readers that consumers plug these computers (routers) into their networks all by themselves without any assistance. This makes any argument that consumers cannot plug things into their network hard for me to believe.
Setting up those crappy routers is another issue unrelated to my comment. I don't know how consumers get it done, but they do. I find web interfaces annoying and unnecessary but I know many users love them. Again, this has nothing to do with my comment, which concerns preconfigured images and booting from external media (as on the RPi).