I'm saying LP is the wrong way to write a book about how compilers work. LP might be useful for a toy example compiler as part of the how compilers work book, but that is it. Reading a LP version of GCC is the wrong way to learn how compilers work - once you see one (or maybe 10) optimization you know how they work and can just read source code for the rest - I don't know how many different optimizations gcc has, but I'm sure it is at least thousands. Similar for the parser, there are a lot of edge cases in gcc (C is a terrible language to parse - your compiler example should use something with a simple grammar so LR or other standard parser is used not the mess that gcc must have because C).

You're describing staged learning -- and the example at the bottom of my OP is trying to demonstrate exactly that. My https://akkartik.name/post/wart-layers describes the mechanism in more detail for starting from a simple example and gradually adding concerns.

It's true that the very first example a student sees shouldn't be some eldritch horror in all its complexity.

It's also true that in the real world today, people study eldritch horrors on their own after learning the basics in kiddie pools.

But we can do better than the way we've always done it. For key pieces of software that have eaten the world, it seems worthwhile to gradually chip away steps on the cliff side to help future learners more easily understand the real-world complexity.