I think a lot of people are blaming Dair unfairly for causing ratings problems but I think its a much bigger issue here is that the writers are simply terrible and it goes all the way back to season 3. Everyone was excited for Chair and instead of going for telling a simple tale of a relationship they did ridiculous plot lines involving Chuck mother and Jack. I think it would have been better that season to just see Chuck just trying to be boyfriend Blair, which would have been comedy gold.