Another follow-up from yesterday's doc reviews

The comments in the file say that we *must* use load-asdf to load a .asd file, but not *WHY* we must do so. Why is this necessary? E.g., I have a makefile that lets me build a number of executables using my choice of lisp. Each time, to build the executable, it starts a lisp, loads the ASDF file (using --load or equivalent), and then uses asdf:make. I could use --eval (asdf:load-asdf "myfile.asd") but why is it mandated?