I think you should read up on how secure boot works with macOS and alternate operating systems before speaking this negatively about the implementation. Apple is already giving you exactly what you’re asking for.
It’s not really even that different than a PC motherboard that gives you “Windows UEFI” and “enroll my own keys” as options.
https://asahilinux.org/docs/platform/security/
As far as code signing, again, what do you want Apple to do here? They already gave you a master switch to turn it off. You are free to turn it off then implement your own third party code signing solution if you’d rather choose who you trust. It’s not Apple’s fault if nobody else decided to make their own trust repositories and the only alternative on the market is to have no safeguard at all.
And let’s not forget who Apple markets their computers to. These features aren’t for you and me, they’re for the non-technical customers who will absolutely get pwned by unsigned code. Go to the MacBook Neo marketing page and try to find a single image of someone writing code or even being gainfully employed.
This is that false dichotomy.
You can turn off all protection, as you point out. So who Apple markets Neo's to isn't a factor.
> Apple’s fault if nobody else decided to make their own trust repositories and the only alternative on the market is to have no safeguard at all.
Does Apple provide a means for enabling third party trust systems, without disabling Apple's protections in general? If not, that is a serious problem of Apple's choosing. Nobody (to a first order approximation) want's to dispense with Apple's protection, or re-implement it, but to be able to carve out exceptions for specific classes of software.