Here's my list of things that pissed me off, and I only made it up to around Ep. 18:
-Removal of permadeath, addition of ability to log out. That alone killed it; virtually all of the drama was derived from the fact that when you died in the game, you died, and you couldn't log out. That first fight in the fairy game where teenaged-student-kun saves the stereotypically busty blond elf that's secretly his sister(-except-not-really-she's-totally-his-cousin, people!) from the PKers... I was just slamming my face into my desk at that point. WHAT THE ACTUAL FUCK!? That sort of drama was appropriate when people could die, but then they start talking about exp penalties and WHAT THE FUCK.
-As above, suddenly sister-but-not-really-she's-his-cousin-we-swear-so-it's-okay incest fetish girl is inserted apparently as a romantic foil for Asuna, despite the fact that nameless-protagonist-kun and Asuna were married and living together as a couple with a(n admittedly AI construct) child through the first half, and that all of his efforts are dedicated to freeing her, and there's ABSOLUTELY NO FUCKING FORESHADOWING OF THIS BULLSHIT it doesn't make SENSE!
-Sudden shift in antagonist. First dude was cool, young scientist type with unclear motives for trapping 10,000 people in a VR death game, but was bro enough to trap himself along with them and help lead them from behind a disguise. And was then bro enough to give them an out, and even when he had basically won he still let everyone who lived out, and was a decent enough fellow despite killing thousands of people.
AND THEN SUDDENLY CREEPY PEDOPHILE WITH ELF FANTASIES. Whose motives are basically split between "Develop evulz VR brainwashing technique for an unnamed evul American corporation" and "trap an underaged girl in a game so that she can't object to their arranged marriage, thus allowing him to have her comatose body dressed in a wedding gown before he rapes her". NOT EVEN FUCKING KIDDING. WHAT THE HELL.
Oh, and then there's the "LOL you won't let me sex you, but I could always brainwash you into doing it. But that would be too easy, so I'll just be a really slimy "nice guy" and HIGH FIVE STOCKHOLM SYNDROME!" I mean, shit, I don't think I've ever in any medium seen a villain openly announce that he's going to attempt to induce Stockholm syndrome in a minor so that she won't object to him raping her.
-Speaking of Asuna.... Shit, this is the one place where I can almost agree with what they did, on purely logical grounds. It's... actually a reasonable choice to, when you know that your captor can literally mindwipe you, and that even if you escape your physical prison you're basically trapped in a pocket universe belonging to your captor, to just gather information and bide your time. BUT I'M STILL PISSED THAT THEY TURNED A BADASS INTO A STEREOTYPICAL PLOT COUPON PRINCESS. COLLECT ALL THREE FOR A FOUR DAY EXP BOOST, MOTHERFUCKERS.
In case you couldn't tell, THIS FUCKING PISSED ME OFF. It's like they fired the entire production staff after the conclusion of the SAO plot and replaced them all with brain damaged chimps. Brain damaged chimps determined to hit every taboo fetish they can.
OH I ALMOST FORGOT. FUCKING MARTY STU-KUN. Absurd power level bullshit was borderline acceptable when there was backstory justifying it and it didn't keep him from BSODing after continually failing to protect people without plot armor. Now? LOL u kep ur superpowahz for no adequately explained reason (SAME GAME SERVERS AND PROGRAMMING MY ASS, cheapest copout I've seen in a long while), there's no risk for anyone, the villain is too evil to win, enjoy your BULLSHIT TRAIN.