Garrett: Why UEFI secure boot is difficult for Linux

You are missing a serious part of the picture here. SecureBoot by itself just secures the OS kernel. An OS supporting SecureBoot is expected to use the Trusted Computing modules to protect runtime services and Administrator-level processes. The end result is that even if you get a virus somehow that gets into the kernel, you can just reboot into Safe Mode and clean it out safely. Without Secure Boot, you can't trust any of the other security measures to still be effective, so the only recourse after a compromise is to wipe everything and reinstall from scratch on new hardware with clean firmware. Which can range from "annoying" to "prohibitively f**king time consuming and expensive."

All security is just risk management. Nothing makes you 100% safe, but you can take steps to make yourself safer than you were before. By your logic, we might as well remove security levels, passwords, sandboxes, and firewalls, since none of those actually stop a dedicated hacker from getting into your systems. Obviously you don't believe that because you know that they add some value and reduce risks. SecureBoot is just another small step that reduces those risks a little bit more.