MPW was certainly Unix-inspired, but its multitasking was seriously deficient compared to a real Unix. Its runtime environment couldn't run more than one binary executable ("tool") at a time — not even using `system()` — so MPW's Make couldn't actually run anything, but merely printed out the commands. Only the user and MPW Shell scripts could execute other programs.
I wrote about this at length in part two of this article on MacRelix:
I wrote about this at length in part two of this article on MacRelix:
https://www.metamage.com/text/relix/origins.html