Personally, I don't mind when someone says "I didn't care for this episode/season/ending/etc". That's a perfectly rerasonable thing to do - it's an expression of your personal taste.

What bothers me, is when people start criticizing the writing, directing, and/or acting but have ZERO experience, talent or history doing those things successfully themselves...

It's like ordering a specialty dish at a restaurant and instead of saying, "I don't like this dish", they proceed to explain how the chef doesn't know what they're doing.

Just because you don't like something doesn't suddenly make you the expert. In fact, it's pretty clear that these writers and directors know exactly what they are doing given the success of this show, and it's pretty much a cabal of nitpickers and would-be critics that like to pretend they know more about writing & directing than the professionals making millions of dollars doing it for a living.. I won't even get into the plethora of far-fetched theories they cook up based on the egocentric opinion that they know best because they've predicted how the story "should go" and then piss and moan about when things play out differently than they imagined.

However I don't blame the show or GOT fans for this problem.. because it's the internet.. it gives these types a platform to INCESSANTLY post negative things about nearly everything successful or popular - you don't have to look hard to see it.. just look at the comments on any celebrity tweet or news article.. there's an entire society of trolls waiting to tear down anything they can because of their own miserable lives or delusions that their opinion is somehow more valid than everyone else's. Because you know, they know best. I mean that's why they have written several successful books & movies and directed their own HBO series, and D&D's "ineptitude" is evident to them because they know so much more.