I very much disagree, in the general case. The complexity of embedded systems design can't be significantly reduced by using python and I often do not think while developing that I higher level language would help, in fact I often think that C maps very well to the problem. It was designed as a system programming language and is good as one.

The complexity of embedded code does not lie in the code itself but in the hardware and you have sacraficed a few orders of magnitude in speed for very little or no gain. The code itself is usually fairly simple but you would not be able to tell anything from looking at it, you need to refer to datasheets.

Not only this but by using an more expensive ECU to begin with you really limit the scalability of your design and add to recurring costs.

I use a more powerful microcontroller at work and we still constantly have to drop down to assembly, albeit in limited controlled ways.

That said, there will be areas where this is a viable option, but not many. You have to analyze your problem and decide if is viable; for an embedded webserver it is, for a DCDC converter where speed is of a concern it is not. For a smoke alarm where cost is primarily a factor and your margins are tiny it is not.