And why exactly a predictable film can't be great?
I quite agree that it doesn't deserve so many awards, and for me it's a 7/10 (didn't like how they switched from explaining how he knew the answers to the love story), but your points are highly debatable. Good acting doesn't make a good film (see Doubt), neither any of the other components in separate, it's the sum of all parts that makes it, and they don't have to be all good. It helps, but it's not mandatory.
Oscar awards are an expression of how the academy sees film, not public in general. I follow oscar awards for quite some time, and the main reason is too see films that I otherwise would ignore.