Compilers

Only if they get a copy of your software. As long as you don't share the software itself nobody can demand anything from you.
The Open Watcom license does require you to publish your source code even for people who don't already have a copy of the software, which is why the FSF considers the Open Watcom license proprietary.

I am still forced to do something instead of posibility to do it freely

And as a producer with a goal to make money, I don't know why one would ever consider GNU. It also prohibits you from selling to any of the various walled gardens, which people clearly enjoy. (Apple, Google stores etc.)

Will they ever learn?

**Permissive = anarkiddies (goal: personal freedom)
Copyleft = fascism/natsoc (goal: group's freedom)**

Good idea. We need race and ideology specific licences.

they already exist rust-lang.org/en-US/conduct.html

no, and even if they did they could do inhouse gcc extensions too without having to release them. companies are scared of the evil "viral" copyleft boogeyman.

gcc
cucklang

Depends. Clang has some advantages (compiles faster, is much easier to extend, license). But so does gcc (works on anything, license). Which produces better code depends, I've seen huge differences between the two for both sides (usually, but not always, icc > gcc > clang). Very long-term clang has the advantage since their code is less fucked because it's more recent.

You only need to release the code to your users. Since the project is private you have few users and can add in the contract they can't develop a competing software.

You don't always need maximum speed. Often you only need "does x before y seconds pass". Take the guidance software for a rocket for instance. You can afford wasting a few more watts to avoid some crazy bug.

If I require reliability I'd already be solving the problem with three different builds of the program where the output is compared so I could detect and recover from program errors, tool errors, random errors, hardware faults, physical damage (combat aircraft), cosmic rays, etc.. A slow as shit "formally proved" language is of little value since I'm not going to be putting all my eggs in one basket.