There has to be another option other than either having a hardcoded master password or being unable to help customers back in once they mess up. If you've messed up the device a physical hard reset button would do the trick. But it would be a pain for anyone who just forgot a password and doesn't want to lose settings. So how about a physical "reset my password" button? Press it and the next time you connect over the LAN it forces you to choose a new password, but doesn't erase your settings. Wouldn't that work and eliminate the need for a hardcoded master password? Disclaimer: I may fall into your "nerd" category. But I still like devices that just work without 8 hours of setup.
I've got a couple Netgear Nighthawks. One of them is running Advanced Tomato. If I want to get in to the Netgear firmware using an admin password, I have to hit a button. If I want to get into Advanced Tomato, I don't. I don't need to hit a button to install Advanced Tomato over the Netgear. And I'm not an expert. I'm a dude who can follow directions. I, too, like devices that just work without 8 hours of setup - but generally, those are the ones that IT guys slag on you for running.