Daniel Carlson details one of many reasons:
[A]wards coverage treats movies as if they exist only for the few weeks at the end of the year when studios put out “prestige” titles that are designed to capture award nominations. There’s no real secret to why they put out these movies at the end of the year: our brains look more fondly on recent experiences, so studios want films to come out as close to the nominating cycle as possible. There’s also a self-fulfilling prophecy involved; since the end of the year is now associated with award contenders or prestige titles, releasing your movie at that time can give you a subconscious boost in the mind of the voter. But movies exist long after a particular awards season has ended. That’s why the notion of “great movie years” is flawed; it assumes that, e.g., Inside Llewyn Davis exists solely as an artifact of 2013 that was created to compete in a few arbitrary competitions, instead of treating it as a film that anyone can watch at any time going forward. It’ll still exist next summer, and the year after, and ten years from now, long after we’ve forgotten every fleeting pop culture story from the 2013 awards.
And then there’s the hathos of many of the hosts.