I'm no ios dev but my thinking was that it was done this way for flexibility. So one internal framework could be developed entirely separate from the other app

I'm no ios dev but my thinking was that it was done this way for flexibility. So one internal framework could be developed entirely separate from the other app code. And maybe one framework gets updated with a new dependency before the others. Either way, this "analysis" seems pretty superficial. I can run a "du" of almost anything and it won't tell me much. And this author misleads intentionally by giving no explanation, but the implication is very clear from the post that Facebook is lazy and sloppy with disk usage.