Is it not just making things more complicated to put some CSS separate and some at the component level? Sounds like a nightmare for a designer who comes in to the game that didn't design the app.

I'm not saying breaking CSS into separate files is a perfect solution (this is what I do), but at least it allows you to have everything in one place so anyone can pick up and customize.

I work with some pretty complicated enterprise CMS systems and they are already terrible complex. Last thing I want to do is start spreading CSS all over the app.