Personally I adore Deadire. Yea the main storyline is so so and very short HOWEVER that is NOT how to play this game. I clearly was designed for you to explore the lore and get immersed in the world; and it works beautifully at that. When I play this game I completely ignore the main storyline lol. You have a boat load of stuff to explore and discover.
So nice to find someone else who sees PoE2 this way! It's exactly how I approach the game as well, and why I love the game, because I have always wanted a good party-based cRPG where I can afford to pretty much ignore the main quest line for as long as I want and just wander around and do whatever I want without any pressure to follow the script. The problem in PoE2, of course, is that even though the game allows you to do this it really shouldn't, because major God-guy looking to destroy the world as we know it an' all .... So there is that disconnect in the game, and it's understandable this bothers some people.
