Following yesterday’s Linux 6.18 kernel release, GNU Linux-libre 6.18-gnu is out today as the latest release of this free software purist kernel that will drop/block drivers from loading microcode/firmware considered non-free-software and other restrictions in the name of not pushing binary blobs even when needed for hardware support/functionality on otherwise open-source drivers.
With Linux 6.18 there are more upstream kernel drivers dependent upon binary-only firmware/microcode. Among the drivers called out this cycle are the open-source NVIDIA Nova-Core Rust driver as well as the modern Intel Xe driver. Nova-Core is exclusively designed around the NVIDIA GPU System Processor (GSP) usage and thus without its firmware the driver is inoperable. Similarly, with the newer Intel Xe driver depending upon the GuC micro-controller without its firmware the support is also rendered useless.
They’re not saying devices shouldn’t be programmable- they’re saying if they are, users need to have the right to control the software that runs on said device.
For the FSF it’s not about what’s more “secure” or less complex, but rather whether there’s freedom to be had. In the one case, having rights to view and modify the source gives the user additional freedoms they otherwise don’t have, e.g. to apply security patches as you point out. In the other case, it doesn’t, because even if they could view and modify the source, they can’t make changes to their device with that ability even in principle. Note that, in general, the law does not prohibit users from modifying hardware that they own, so that’s not an issue of freedom. But software is.
Having a circuit diagram for a chip you own is cool, but it doesn’t allow you to change an IC- you don’t have the practical ability to do that. Likewise if the “firmware” is permanent- viewing the “source” is maybe technically interesting but grants you zero additional abilities. If it’s defective, it’s the same as buying a defective IC. Tough luck.
You can choose not to care about the additional freedom you get if you’re allowed to view and modify firmware for programmable devices you own, and that’s fine. It’s typically not meaningfully important for me either. But it’s absolutely not an arbitrary line.
Why do you say it matters where the firmware is being executed? Is it less important to control less powerful computers you own? Why should the code suddenly be unimportant if it’s not executing on your main processor?