It depends what the criticism is to be fair. There are perfectly valid criticisms to be made, and I'm not for a second suggesting I am the arbiter of what they are, but an awful lot of this thread is preoccupied with moaning about things that have been explained because the poster wasn't paying attention. Another great portion of it is people subjecting GoT to a greater deal of scrutiny than they do virtually every other TV series because of the popularity of the show, and their desire to be contrarian.
I think the biggest problem is the source material though. When GoT was universally agreed to be 'good' it was a time when it was world-building, unwieldy, and vast. Boiling that down to a tight narrative that lives up to the world that was created was always a challenge, and I understand it's a similar problem that GRRM is struggling with in the books too.