Plot and writing
Even people who still like the show admit the writing is pretty awful. And it really is. Nothing makes sense. Ellaria decides to avenge Oberyn by... murdering his entire family. And no one seems to have any problems with a bastard woman taking over Dorne? Arya is a hot fucking mess. She kills the Waif, who hates her for no apparent reason, and this makes her no one? Stannis getting annihilated by Ser Twenty of House Goodmen, then deciding to burn his daughter because they've been without food for like a day, even though he's the man who survived the siege of Storm's End by eating book leather and rats for A YEAR? Robb deciding to say fuck it to his marriage vows and marrying Talisa because YOLO (as opposed to doing it for honour, which creates a parallel with Ned, hmm, it's almost like this is a THEME or something) which leads directly to the deaths of him, his wife, his unborn child and his mother. Nice one, Robb. I could go on.
Westeros Jetpack Joyride
Every character has a jetpack and Westeros exists in a warp that distorts time. This is the only explanation I can think of for the timeline. Yara goes from the Iron Islands to the Dreadfort in less than a season, even though this would require sailing around the entire continent, but Gilly's baby is still a baby and Myrcella has been in Dorne for years! Littlefinger is a most industrious teleporter, zipping from the Eyrie to Moat Cailin to Mole's Town in a matter of days, apparently. Sansa and Jon's walking tour of the North takes months, presumably, but Cersei's trial is "in a few days". And Jaime got all the way from Dorne to King's Landing, but Doran has only just received news of Myrcella's death?
This attempt at a coherent timeline makes for fun reading.
All the -isms. All of them.
Game of Thrones is sexist. And racist. And homophobic. And ableist. Rape is used for shock value, and the patriarchy exists except when it doesn't (that fucking dinner scene at Horn Hill, urghghghghgh). No, Dany, Arya, Sansa, Brienne and Ellaria brutally and remorselessly murdering people is not "empowering". Violence isn't empowering. Violence is just violent.