With Morrison I can't help but think it's intentional, of course. How could Dick OR Tim be Bruce's son? They don't have his courage and righteousness encoded into their DNA!
I don't think I've gotten that from Morrison's treatment of Dick and Tim. He did make Dick the new Batman after all.
And I do wonder if Dick's lack of use in RIP was down to the fact that it would be hard to actually make it work with a sane, practical, guy who was almost Batman's equal and who wouldn't get idtracted by Hurts bullshit.
Tim is a better Robin no doubt, but in many ways, Damian needs to be Robin MORE than Tim does. Tim will (hopefully, stay on the right path whether he's Robin, Red Robin or just Tim Drake, with Damian he needs to be Robin to direct his anger and teach him what his father is REALLY all about, and as he does appear to be starting to learn, it's not just down to who's the biggest arse kicker.