OUR IDIOT BROTHER: the tale of an unmotivated Forest Gump

Bring back capital punishment! (for those of you reading this in a territory where it no longer exists).
For all other places, this film is the best argument I've yet seen for keeping it.
OUR IDIOT BROTHER does not deserve to live.

I'm struggling to remember the last time I watched a film that was such a complete and utter waste of space. There is no argument that can be put forward to justify the continued existence of this pathetic wretch. It is totally without worth.
Director Jesse Peretz ('The Ex') has created a shapeless, sprawling, meandering story which wanders around with very little sense of direction but an unfortunate and burning passion for cliches.
A shaggy haired, heavily bearded Paul Rudd is Ned, the titular idiot brother and Beach Boy Brian Wilson look-a-like, while Zooey Deschanel, Elizabeth Banks and Emily Mortimer are his long suffering sisters. After a spell in prison for selling marijuana to a uniformed police officer Ned goes to stay with each of them and - through his stupidity - succeeds in wreaking havoc in their jobs and relationships.
Which is where the cliches come in. There is nothing original about what Ned does or the lessons that everyone learns from their interactions with him. Ned's unfortunate siblings and their spouses/partners see him as an idiot but director Peretz desperately wants us to believe there's a native intelligence guiding this man-child's actions. His chosen method of persuasion is to have Rudd play Ned as a character who is neither completely idiotic nor a total man-child. This is achieved not by a careful blending of both traits but by having Rudd play some scenes as an idiot, others as a man-child and yet others as a reasonably normal person.
The result is a completely inconsistent and implausible character who switches at random between the different forms of behaviour depending on the requirements of the particular scene, and the end product is a viewer as exasperated as Ned's siblings.
The take away from all of this is that it's better to go through life as an idiot than to attempt to achieve something with your life. Sure Ned's sisters are making a hash of it but at least they're trying whereas he's content to not only sponge off them but inflict uninvited life lessons on them by interfering in their lives. While they're left to pick up the pieces (and, of course become better people because of Ned's intervention) he blunders on, seemingly unaware that he's on a road to nowhere.
And that is exactly where this film goes - nowhere.