I feel your passion, but I feel this is a little hyperbolic? I feel your passion is directed more at UEFI secure-boot than at Linux. I am no lover of the UEFI secure-boot world, using shims as a first-stage boot loader component whose job is to bridge the firmware’s trusted key infrastructure (typically Microsoft’s signing key) to a Linux (or other non-Windows) bootloader/kernel chain.

> Linux is under control of the same companies

Linux is indeed open source, so are you trying to say that "Linux is EFFECTIVELY under control of the same companies VIA UEFI WITH SECURE BOOT ENABLED"? Or is there a big-Tech cabal controlling Linux in another manner? I get that most big-Tech companies are major contributors to open source projects.

> all major distributions (Debian, Fedora, Ubuntu) ship with a shim signed by Microsoft

Having a shim signed by Microsoft makes no difference if these distributions are being installed on hardware without UEFI firmware implemented on the motherboard’s SPI flash e.g. motherboards from Purism (Librem Laptops), System76 (Thelio, Galago Pro, etc.), Framework Laptop (2021 →), Star Labs, Raspberry Pi / Single-Board Computers and uncountable DIY PC builds with motherboards (ASUS, ASRock, Gigabyte, etc.) that expose Secure Boot options. It is usually only when consumer hardware is being used from major OEMs (Dell, HP, Lenovo, etc.) that ship with only Microsoft’s key in the firmware trust database.

> and systemd

You are suggesting that “systemd” is also part of the lock-in or control (in your mind) of those distributions. But strictly in the context of shim and Secure Boot, systemd is not the same issue: systemd is an init-system/process manager in userland, not part of the firmware/boot loader signature infrastructure. Major distros use systemd, so from a “vendor/lock-in” narrative they may lump bootloader trust and systemd governance together. But strictly speaking your assertion is more of a opinion/ideological piece than a formal technical dependency.

> *BSD is the only escape

Not true. Not all Linux distributions use it — Tails, Qubes OS, PureOS, Alpine, Void, Gentoo, etc., deliberately avoid it. Most minimalistic, privacy, or DIY distributions refuse the Microsoft-signed shim route because their users are expected to control their firmware settings or use owner-controlled keys.