The problem with macro-laden C is that your code becomes foreign and opaque to others. You're building a new mini-language layer on top of the base language that only your codebase uses. This has been my experience with many large C projects: I see tons of macros used all over the place and I have no idea what they do unless I hunt down and understand each one of them.
Obligatory link to Bourne Shell source code. https://www.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/sh...
Discussed here https://news.ycombinator.com/item?id=22191790
I think this can be fine if the header provides a clean abstraction with well-defined behaviour in C, effectively an EDSL. For an extreme example, it starts looking like a high-level language:
Like the Linux kernel?
Macros are simply a fact of life in any decent-sized C codebase. The Linux kernel has some good guidance to try to keep it from getting out of hand but it is just something you have to learn to deal with.