Earlier quoted context omitted.
What happens if you run it on itself - eg you do some sort of basic program with a little bit of structure and generate code from it, and then analyze the code, eg to make a graph of it (if that makes sense). Or to put it another way, what are the possibilities of making better tools Mathematica (or Wolfram Language or whatever it is called now) using Mathematica?
It would be slightly easier than coding Mathematica from scratch (you have better computers and an example to follow) but much harder to fund, since you would be re-treading old ground and wouldn't be able to competitive for a long time. The types of problems simplified by Mathematica don't include coding Mathematica. To be sure, it pioneered a few nifty techniques that you would want to take advantage of, especially…
I agree with your general comments, as I hate writing glue code and my interest is primarily for DSP and simulation applications, for which I already admire it.