I think this is going into the wrong direction. In my world "plumbing" means realizing ways to do things. When you want to write a simple web app that shows a Hello and has a contact form: even in 2018 that's still a reasonable amount of work. It's really not a lot of code but every line needs to be chosen wisely. That's what I call "plumbing". Most people new to Software Development become desperate at such tasks and to the rest it becomes embarrassing quickly... :-)

Yeah and then there's actual code writing: the heavy lifting has been done, all the functions/classes/modules/... are still small and wait to be stretched with a lot of nice code. In well sorted projects the latter is a trivial tasks for simple features.

But yes, I agree with the sentiment that there is a lack of general "understanding of stuff". I'm not sure if you must be able to use strace to be productive but it sure helps if you're able to get to know tools that are installed on most systems. Coming back to the OP's topic: LISP is a language that uses formalisms (ways to plumb ;)), tools (ever heard of asdf?) and syntax complete alien to even long-term computer addicts. It always puzzled me how people can be comfortable using this kind of stuff.