I found it completely sincere, shows how easily people's vocal inflections and body language can be interpreted in many different ways! And please point to any evidence whatsoever that she's 'desperate' to win the Oscar, as everything I've read suggests the complete opposite - she's grateful to be nominated and would love to win (like anyone, so what's the problem with that?) but there's no desperation whatsoever.
Of course the Oscar holds more weight, but she's won almost every award going so far this awards season, so it wouldn't be too presumptuous for her to at least think a bit about what she'll say if she wins. She doesn't seem the type to become a Halle Berry-esque emotional wreck - I think she's more likely to give the Helen Mirren/Reese Witherspoon type of fairly calm speech than the Kate Winslet/Penelope Cruz blubbing.
She's far from my favourite actress, in fact Les Mis is only the 2nd thing I've liked her in (the Devil Wears Prada being the other), so I'm not a huge fan jumping to her defence regardless, I just can't see her being accused of desperation and insincerity and not comment, as I've seen nothing to suggest that whatsoever.
The whole "a weapon against self doubt" line was just awful. It's almost as if she needs these awards as a way to validate her acting and reassure herself. She just seems far too desperate to please people. Then there's her need to try and be funny all the time when she's blatantly not.
Each to their own I guess.