Comment by dmix

CSS isn't exactly a clean language. In my experience most projects are write-only... CSS just accumulates. It is rarely refactored or carefully designed. It is only occasionally mass deleted in redesigns and redone. Having a standard namespace pattern eliminates a lot of hierarchical issues, which is a very common issue with CSS.

Utility based libraries tend to avoid this these days and use simpler names, but those are also supposed to be your root libraries, not your custom CSS.