Personally I haven’t seen this motive across any of the organizations I’ve worked at. They usually seem more interested in minimizing maintenance costs, which means they try to upstream changes where possible or practical.

What would motivate a company to fork and keep private changes to a core GNU utility like chmod?

Any hardware company which would want to block 3rd party firmware from loading or executing on their systems. They can add a small handshake code to every binary on that system to authenticate via TPM or the processor's embedded secure element on start.

They don't need to make extensive changes. Pull the latest, patch, compile, burn to FW. TaDa!

IOW, TiVoization 2.0. GPL2 makes it very hard already, but GPL3 makes it impossible.

With permissive licenses, it's very possible.

ref: https://en.wikipedia.org/wiki/Tivoization

> What would motivate a company to fork and keep private changes to a core GNU utility like chmod?

Maybe ask these folks: https://www.busybox.net/license.html

https://en.wikipedia.org/wiki/BusyBox