i personally feel exactly the same way as you do. While i’d love to tinker around with the codebases, i also believe that these living and expanding ecosystems do not need to be open sourced.
In the same vein though - i would have loved to see legacy products to be opened up to the community.
The last point you mention, is the thing i am most interested: to have the ability for the community to build tooling around the existing ecosystems that does not interfere with the actual devices.
Which is exactly why i created this wish a while ago:
While this was created in reaction to the removal of .mod and .it support. The intent of this request goes beyond that and is meant to benefit the overall ecosystem.