See, I think it would have been a fun little Easter Egg had it been implemented a little more subtly, rather than just throwing it up there like that. It's so in your face it feels distracting.

As for my other complaint, that's really less of the movie than it is towards the fans. Everywhere I've read, including here, seem to treat him as a Robin, simply due to his name. If you go to the Wikipedia page on "Robin," John Blake is listed as a Robin. Which, as you just said, makes no sense. So, because of this stupid little Easter Egg, everyone suddenly believes he's Robin, which overshadows his actual purpose of becoming Batman. And since the whole theme of the movie, or, hell, the trilogy, is that Batman is a symbol that can be carried on, that's no small point to miss. So I just think Nolan shot himself in the foot by putting in this over the top, pointlessly silly Easter Egg.

EDIT: Come to think of it, though, calling it an Easter Egg is really a misnomer. An Easter Egg is called that because it's hidden. Not everyone is going to see it. It takes attention to detail or an especially honed knowledge of the fictional world to even pick up on it. When you take something as well-known as the name Robin and stop your film just so a character can say it, that's not an Easter Egg. You might as well be winking at the camera at that point.