So often recent breaches involve Github in one way or another. How is it still considered a sane choice to host anything proprietary there? If your business is built around open source, ok, put a mirror on Github. But CI/CD, gitops, FDEs' stuff have no place on a public cloud. C-level execs may not know bits from bytes, but by now they should've understood that this is akin to storing ammonium nitrate in the open air.

This wasn't GitHub's fault in any way.

So many security breaches involve Linux in one way or another. Your argument doesn't really work.