The word "monoculture" means something completely different. LLVM is by definition no "monoculture" because it integrates a diverse set of function and is developed and maintained by a diverse set of people, and there is a plethora of versions and applications. With your definition each country or company would be a monoculture; and mathematics would be a monoculture because it always applies the same rules; and all fuel driven cars would be a monoculture; and electrical engineering would be a monoculture because everyone applies Maxwells laws; you name it. This misuse of terms is done with the intention of creating a negative connotation where none is justified.