It's that we (the people) get slammed by DMCA violations for taking someone else's content (for private consumption). When a huge corporation takes ours (and gets paid for it), what recourse do we have?
It's that these corporations can change the rules on us in the middle of the game. It's the classic bait and switch.
It's that we're not even getting asked or given credit.
The Instagram developer page (http://instagram.com/developer) says users own their images. They expect third party developers to respect that. Why won't they?
Who fights for the user?