I think you're both right and wrong here. You're right that this often causes problems. Anybody who has tried to salvage an iTunes library can attest to that.

I think you're both right and wrong here. You're right that this often causes problems. Anybody who has tried to salvage an iTunes library can attest to that. However you're downplaying the positives to having a metadata database, and you're also ignoring the teeming masses who don't care about the layout of the file system as long as it's displayed in the app.