Owen got busy being a movie star, even by TRT Wes was writing most of the script and would kind of confer with Owen about it.
His best performances are still in Wes' movies, so even if he's not writing with him any more (which it would be great if he did at least once more), there's still that.
I don't know, "Midnight in Paris" is up there with his best performances (Golden Globe-nominated, for what it's worth). But it is worth considering that, to date, Owen essentially plays himself (or rather his established screen persona, if you'd prefer to think of it that way) in every single film he does. Which is not a bad thing.
Having said that, I miss Owen, but his absence in "Moonrise Kingdom" is certainly nothing to brood over. Unless you really want to, that is, which means the problem is not with Owen and Wes, but with us as onlookers, I suppose.
That last sentence was far too reliant on commas.