If Lambda open sourced the engine, but didn't make it super easy (as in a 1-button deploy, nothing intentional) to stand up your own stand alone Lambda service, would that be better?
On my projects that have been open sourced, we mostly open sourced to make debugging easier and make extension authoring easier. I've gotten comments from people that that makes them feel easier about vendor lock in, but honestly, I haven't seen many people try and stand up their own service. Would you say that matches your own expectations?