Why was Blitz left out by awards bodies?

It's hardly a bad film especially in certain categories. It looks visually great, the production design was excellent. Saiorse was as strong as ever. Renowned director.

Are the people generally just tired of WW movies at this point? Especially ones that aren't 'at the heart of the action' so to speak? Was it just that this year these were more intriguing and interesting projects made overall?