What I know is if projects use permissive licenses, the software end users getting is usually proprietary.
Copyleft is designed to prevent that from happening.
What matters is whether they contribute back anything to open source. And it's a hell of a lot easier to get Legal to sign off on contributing back bug fixes and enhancements on a piecemeal basis rather than adding a recurring obligation to the books.
A lot is companies would have preferred to have proprietary operating systems, but the Linux license prevents them.
I don't see this as a valid point.
The point of copyleft is to make this not true. Most companies don't have the resources to reimplement Linux from scratch, so they won't be allowed to make their drivers/kernel modifications proprietary.