It's not a bolted happy ending. It's his resolution as Bruce Wayne.
I sure can.
It most certainly is.
There is nothing in TDKR's end that is cohesive with BB or TDK and even TDKR in a lot of ways.
For three movies that put focus on Bruce learning that loss and forgiveness are major parts of his life. That sacrifice and resolution are reoccurring themes in his actions, TDKR just seems to throw at us a "and they lived happily ever after" ending at us without much of a basis.
"I don't have the luxury of having friends" Says Batman at some point but throughout three films he creates a network of them who fight on his behalf and support him.
"This power is too much for any one person to hold." This is his common excuse against the nuke thingy and his Bat-computer. Yet both can provide a great cause of good for the people of Gotham.
Alfred says: If you gave it to the police they could do their job's better. But Bruce is too distrusting of Gotham to do that.
...and in the end he's still too distrustful of Gotham to do that? After years of fighting along side Fox, Alfred, Gordon and the GCPD he gives his entire arsenal to...someone he just met and has ascertained his identity through ridiculous means?
"Batman has no limits"
"Batman has no jurisdictions"
There were CLEAR ideas that Batman and Bruce would go wherever they were needed to save Gotham but TDKR's end suggest that he just stops one day because he's tired of it? Now I'm not proposing that he had been Batman forever but at least a better reason to stop being Batman.
Death would have been a great one. Just like Thomas and Martha's death galvanized Gotham and then Harvey now...Bruce. No masked heroes needed. The idea that Batman could fight crime but would create Jokers and Brian Douglasses was what TDK was about. That Batman was a blunt instrument for one purpose and that purpose would never be to inspire Gotham but to protect it.
That's why Harvey Dent is the one Gotham is looking at in TDK. Because he IS one of them. That's why Gordon is a hero in TDKR because he's IS one of them. Batman is a wraith, a thing in the night. A watchful protector blah, blah, blah but he's not human and he's not a Gothamite.
So to see Batman die and Gotham praise him whilst Bruce Wayne has a vacation in Italy felt totally tacked on to TDKR's ending and opposite of the other two films, for me.