They only care because open-weight helps to drive the GPU business notably thanks to inference providers (Baseten, Together, Mistral, ...).

At least their support helps the open-weight ecosystem.

Depends on which open source you are talking about, like every single company contributing to FOSS.

They care when the agendas align, and they don't when they won't.

They certainly do _care_. Embrace, extend, extinguish.

They don't. I got threatened with a lawsuit after I suggested (submitted patches) they fix some of their buggy kernel code.