SAO is a great example of how to take an interesting concept that had rarely been done, and completely ruin it. Yes, I will take whatever dislikes come from saying that but it's true. There was potential to make something great and it was ruined by short rushed arcs, the inability for it's creators to keep it in their pants long enough to tell a compelling story instead of jumping into fan service, and the idea of leaving SAO was the absolute worst thing that could have happened to the show. Any real stakes of drama were lost the first time we saw what a god character Kirito had become and how everyone outside of that first guild that he cared about had all the plot armor they needed to never really be in danger. Also the tsundere gimmick is bad enough as is, but adding to by speeding it up to the point where most would question why it's even there, just makes it worse. Also every character being defined by where they fall into or out of the pointless harem that came too late to matter, just makes everything one note and stops all character development from ever happening. SAO is one of the best example of how to waste potential.