Note: These are my opinions, you are free to disagree with them. Please be civil if you disagree.
Steve Harrington is overrated.
Yes, he's a great character who's developed a lot since the first season, but he's just... idk he's just a guy. He's done plenty to redeem himself for the crap he pulled in the first season. I don't have a reason to hate him, but so many other characters are just better in my opinion.
2. Victor and Virginia Creel weren't good people
This is more speculation than anything, but parents have a bigger impact on a child's life than a lot of people might think. And I know what Victor did in the war was accidental and civilian causalities in war isn't uncommon. But how badly did Victor and his wife mess up as parents to end up with a psycho mass murderer for a son?
3. Kali/008 is an unnecessary addition
We never see her again after those two episodes she was in and then, poof. She is an interesting character... in concept.
4. The haircut need to go
Will's hair needs to go. Nothing else. Shave it off, cut it shorter, grow it out, but please lose the bowl cut.
5. Demo-creatures are predators, not vermin that need to be extinguished
Demo-creatures are meat eaters, yes. But you don't exterminate a group of lions because they eat a gazelle. Same goes for the creatures of the upside down. I'm not saying I don't hate them for killing beloved character's but Dart exists, so there's good in the dimension. And it seemed relatively peaceful before 001 crashed.