In this instance we are talking about data that is already encrypted. Now tell me why anyone would worry about their encrypted data being identifiable unless it's not their data. Not something I have to worry about and suspect majority of users don't need to worry about this either.
For the same reason lots of folks may not want their Netflix queue or Amazon purchase list put out in the public. Or their library lending list. All of those are lists of legal, publicly-available items, but that doesn't mean folks might not want and expect privacy when it comes to others knowing what content they are consuming / collecting, regardless of its legality.
