Totally agree...I didn't buy his character outside of the farm intro. His adolescent daughter was a more convincing "scientist" than he was as the main plot began revealing itself. And it seems they got so invested in the whole dimensional mind game at the end that they forgot the character relationships...taking one of them and just platooning her on some planet while we visited her in time as she was dying. I mean sure, they allude to MM going after her at the end, but really? That's what we get? I could have done with a whole lot less "ghost" talk in the 5th dimension and a whole lot more going to get her and finding out what she was doing on the other world.
Given Nolan's previous project, and the almost perfect balance of character development and satisfying story completion, I was surprised to walk out of Interstellar feeling so underwhelmed, especially with the drool worthy excitement I had building up to the release.