Mine has the same wear pattern pictured, and has never failed.
Remember, the bolt catch is being pushed up by the follower at the end of every single magazine, from the time the last round is chambered until the bolt locks open after that last round is fired.
There is something else going on with the OP's gun if he can insert an empty magazine, retract the bolt, and have it not lock back.
Things to check would be:
1) Is that rear shelf rounded all the way across for some reason (as others stated)
2) Is the pin that is engaged by the follower missing, bent, otherwise damaged, etc
3) (and this is the most likely if it won't lock open even while manually pushing up on the bolt catch) Does the bolt catch move freely up and down in the lower? Remove the upper, and just press the bolt catch in the lower up and down. It should move without any real grittiness or much resistance. Remember, follower pressure needs to be enough to move it through the length of its travel. Working in a little CLP around the post probably wouldn't hurt anything either.