...And second you don't want fast and tiny efficient code on a quad core cpu with 1GB ram. You want fast enough code and you want to write the code as fast, easy and clean as possible.
Sounds like a Windoze programmer. There is nothing wrong with writing efficient code for ANY microcontroller. It is simply good practice, and the mark of a "good craftsman". Secondly, "fast enough" is sometimes a recipe for problems later on if you need to add additional functionality in the area of interest. I have seen some dreadful embedded code written by Windows programmers, with getters and setters all over the shop, and little thought about clock speeds, or readibility, creating one big mess that is barely functional.
Code should not be written as fast as possible, UNLESS it is planned up front. Slap-dash fast coding is often false economy, especially for larger projects. The software should be planned and documented before any code is cut, with planning about resources, clock speed etc. With good planning, the coding time is reduced and the chances of a rewrite is diminished.
I agree in that the code should be easy and clean as possible. That means smart and consistent naming convention, well structured file names, intelligent function calls and interrupt handling, and smart commenting. Most importantly, in any company there should be company coding standards published.
At the end of the day, inheriting someone else's well written code is a blessing. But inheriting crap code can be absolutely soul destroying. Better off in jail than having to refactor some idiot's software.