I agree, I agree with you on a lot of things. But we can't turn back time, but it was a good lesson for us.When there is too much content? I think the game was already perfect with the vanilla corruption of Kerrigan. You could have just wrapped up things there and move to another title.
Its a bit too different in style and tone now than how it started. Lets say you play starcraft 1, middle way of the campaign it suddenly turn into fortnite. The base game was perfect, now its just too different.
If it was completely another game it would be fine in my opinion. It feels like you are trying to satisfy a huge variety of niches and its hurting the overall game.