"quality has to be designed in - not added as an afterthought" - maintainable code in our scope of discussion has nothing to do with open source etc but code written in a manner that is readable to the majority of skilled people and structured in a manner that makes it easy to modify and test.

Doing pointer checks, etc is another layer of thought for writing robust code. Maintainable != robust. You can have code that works and is robust but not necessarily maintainable - it could be total spaghetti code!

I would expect most skilled coders to use all techniques as a matter of course as part of their normal design process. Sure , we sometimes need to write some quick and dirty code to prove something - most people I know would make this code well structured and readable as a matter of course. In regards to the time involved to "add" maintainability and robustness - what you forget now costs more later.

Also, in my earlier reference to the code in fuel injection computers - they were written by humans in assembler - I wasn't trying to decode compiler code - I know what that looks like!