Renderer should not be full of interdependent parameters that do not affect the artistic quality of the image. People should focus on art, not tweaking sampling settings. Corona is already smart enough about sampling, and it will even smarter about it in future. Those are basic principles of corona. No area light/reflection/refraction samples and bullshit like that. So please do not post more similar requests, you will just waste your time.
Also, absence of sampling settings has absolutely no effect on if the renderer is focused on still images or animation, or certain branch of CG industry. Absence of sampling settings has only effect on simplicity and ease of use, and these parameters have their place in both stills and animations, and in all of the CG industry branches.