I think your vision will come to pass. Many of the NSF funded STEM+C projects are doing exactly this: looking for lightweight integration of computing into existing STEM curriculum. Many don’t go as far as even Scratch, focusing instead on tools with simple state and logic to support learning objectives in the Next Generation Science Standards.
Unfortunately, it sounds like the STEM+C project might not survive the NSF budget cuts this year. If that happens, a lot of progress on “many customized focused tools” will be halted.