I'll ignore the ad hominem and bile, Mr. Hater.
Instead I'll fully explain the camera/camera roll switching problem for your edification.
In the camera app, take a photo. Now how do you review your photo?
You tap the camera roll icon and it drops you in the list of all your photos. You then scroll around, looking for your photos and you tap it to bring it up.
That UI is broken and I have heard Android phone users complain about it bitterly.
99% of the time, a user switches to the camera roll from the camera to view the last photo/s taken, not to review the whole roll (pick up any Point and Shoot or DSLR, or take a picture of any 4 year old, if you insist on disagreeing with this point). So why does Android drop you in the camera roll instead of the last photo taken like every other camera in the world?
If the camera dropped you directly into the last photo, there were would be two possible 'backs', back to the camera or back to the roll. But the back button enforces back to the camera so the result would be inconsistent with the Gallery app, confusing and useless since a user expects and often does want to move between the last photo and the other photos in the roll. Google's solution was to drop the user into the camera roll so the back button works consistently and as expected. The usability of the end result, however, is pretty bad.