I think you're talking past the parent's point here.
Firmware as I understand it (also as a microcontroller firmware programmer) is about the same as what the parent understands.
I think your metric about "too simple to screw over the user" is sort of weird, when in the context of my work and the parent's work, "screw over the user" might well mean "disabled the oxygen pump on the user's space suit".
It is in that sense that motherboard Bios is a marginal case. It is marginal in the sense that BIOSes are clearly at the margin between embedded microcontroller firmware and full-blown general-purpose-computer operating system. If I have to update the BIOS on my computer every month (or every week) just for it to boot into any operating system, then something is incredibly wrong, even as modern BIOS have become several orders of magnitude more complex today.
Firmware problems don't have to be severe enough to put human lives at risk to be a real problem. There are tons of examples of bad firmware leading to broken power or thermal management leading to crippled performance or battery life or excessive fan noise. WiFi NICs have subsumed large parts of the network driver stack and in doing so have made it impossible to implement effective QoS, leaving users stuck with stupid radio behaviors that hurt the performance of every device operating on the same channel.
None of what I'm proposing would lead to a bios update every month, except in the initial period of fixing the worst of the manufacturer's mistakes. "Firmware" as I'm using it would still be trying to present a stable interface to the rest of the system and not inherently be a moving target of constant feature creep in addition to the bug fixes.
Firmware as I understand it (also as a microcontroller firmware programmer) is about the same as what the parent understands.
I think your metric about "too simple to screw over the user" is sort of weird, when in the context of my work and the parent's work, "screw over the user" might well mean "disabled the oxygen pump on the user's space suit".
It is in that sense that motherboard Bios is a marginal case. It is marginal in the sense that BIOSes are clearly at the margin between embedded microcontroller firmware and full-blown general-purpose-computer operating system. If I have to update the BIOS on my computer every month (or every week) just for it to boot into any operating system, then something is incredibly wrong, even as modern BIOS have become several orders of magnitude more complex today.