I appreciate default passwords on systems. Often, for routers or other devices, I might need a way to connect initially. Or, if I perform a hardware reset, I want some password that I can use to reconfigure things. However, I am pretty good (not perfect, but really good) at changing those passwords to something else. It drives my wife slightly crazy at times, but I save the passwords and stick them in a manager I share with her periodically.
SQL Server doesn't store a default password when you install it. If you enable the sa account, you need to create your own password. I primarily deal with containers, and I always set one, usually my own default. However, lots of software either allows a blank password or has a default password set on installation. Oracle even lists theirs in docs. That's not the worst idea if sysadmins change them, but if they don't, it's a threat vector for attackers. I was working with a customer last year who had an Oracle database. I asked them to try a default user/pwd as a test and it worked. I think my head was slowly shaking for the rest of the call.
Recently, Silicon Valley saw the result of a default password not being changed when someone hacked the crosswalk signals and uploaded fake audio files that played when the signals changed. The vendor (not surprisingly) advised the city to change the passwords to something strong. A somewhat harmless prank, but it's possible that someone might have made a more nefarious change.
It's 2026. We know there are people out there with malicious intentions, as well as those whose prank goes sidesways and have unexpected side effects. There isn't a good reason to keep default passwords anywhere, including in your own personal devices. These days, connectivity among many systems is a reality with network, Bluetooth, NFC, and who knows what other connections are possible. Your personal devices ought to have defaults changed for your own protection.
Inside organizations, it can be worse as the weakest link can be exploited to gain access to other systems. Quite a few hacks started in test systems and progressed to accessing production data. Even places we might not expect to be problematic, such as version control systems, have been used by hackers to gain access.
To me, finding a default password is worthy of a reprimand and a note in whoever's file forgot to change it. A second offense ought to lead to a suspension at a minimum and possibly termination. This is such a low bar of required security that I can't think of a good excuse to allow it anywhere.