Huh? There has been a camera API since the very first release of Android and it's been systematically updated for the entire history of the platform. What do you mean by "real uniform API for accessing the camera", exactly?
What I mean is snapchat was having issues with using the camera API in android across the variety of devices when they first ported the app to Android (2012 iirc) so they took "the easy route" and captured the still from the live preview instead. The API would work for some devices but not others (I remember other camera app's having similar issues around the same time, mainly not being able to tweak the camera settings within 3rd part camera apps) so basically they said "fuck it" and took the easy path and it just stuck around.
I believe since Lollipop they have been using the new camera API for Android.
