Everything you've just said is compatible with what I've said. The vendors are concerned about being left out at the "source", and are seeking to differentiate

Everything you've just said is compatible with what I've said. The vendors are concerned about being left out at the "source", and are seeking to differentiate with their proprietary "sink", usually closed-source SaaS solutions. I'm not even arguing that this is bad, it's just how markets work, and it's currently beneficial to developers in general, including both open-source developers and the type working in a cubicle farm somewhere.