I did a bit of reading of the main subreddit for the show and a lot of the complaining was about loose ends (what happened to X character?), plot holes and illogical sequences in the final battle and frustration with the amount of meaningful character development some characters did or did not receive. There were also a disturbing about of people upset because Mike didn’t magically turn gay and hook up with Will (???).

I think some of the complaints were fair but the show has been this bad for a long time. All things considered, I actually thought it was a decent finale and it had one of the better open endings I’ve seen. Like with a lot of these character-driven young adult shows, I get the feeling a lot of viewers developed parasocial relationships with the characters and had a hard time letting go. They are in so deep that they lose sight of the fact that the characters and world as it exists in their head is not necessarily the same as the characters and world that are being written for the show. They can’t admit that actually a lot of the magic of the show for them was completely born out of their own fan fiction communities, so when the finale inevitably fails to deliver it’s a lot easier to pretend the show was always perfect until it suddenly wasn’t rather than admit that it was never as great as they built it up to be.