Your argument is anti software freedom. My Windows computer (or any other OS I choose to put on) should be able to run whatever code I instruct it to. The flip side of that coin is that the consequences are mine from doing so.
linux also allows, by approval is decentralized
Indeed, this messup was signed, so correctly it was signed. As for the code/behaviour. It's nothing to do with signing.
Translation: it's up to whoever is the sysadmin is, which probably was responsible for crowdstrike being installed in the first place. Such "approval" would have made no difference in preventing this disaster.
What makes you think that it was installed via windows update? The driver was part of crowdstrike's EDR software, Falcon. It's installed by sysadmins on corporate devices. That's how it got on 8.5M devices. It's not something that gets auto-installed when you run windows update.
I truly don't understand the angle here, besides ignorance.