The primary purpose was to raise money for development of the game. It is incredibly expensive to develop a game like this, and I suspect raising money from EA is better than taking out loans or selling part of the company to investors.
I think Larian erred by soliciting EA feedback and then not acknowledging or responding to that feedback. As far as I am aware, the only change made to the game that Larian has explicitly credited to EA feedback is the reaction system.
It shouldn’t be surprising people who spent a lot of their time providing feedback on early access would become embittered by the lack of response from Larian.
