People, myself included disliked the star crossed lover turn 2 went with following Brood War. Sharp shift from Raynor pledging to kill Karrigan to then being a depressed drunk wanting to save her. That added to the tone being way lighter. Protoss became maybe too high elfy

Terrans, I feel like they flanderized around a basic cowboy western aesthetic rather than anything the confederacy or UED were like in Brood War. A lot more competitive politics for the Terrans in the first game. A bit off that the UED didn't return.

Zerg became a lot less interesting in my opinion. Kerrigan was redeemed. No overmind or cerebrate intrigue. I think many had way higher expectations for a hybrid/xel'naga faction

I remember a lot of complaints about the first 2 games story being long treks to make kerrigan not Zerg and then Zerg again. I don't mind the end or what the Xel Naga ended up being, just the journey not having the weight of the first game. A lack of anger. Faction politics didn't match up the anger of the first game. Felt more high fantasy to me than sci-fi