From a consumer perspective, the game did not change at all. It's the same game I play on mobile, just that I have to pay the same price again to play it on a different platform. Obsidian can charge this, no question. I will still not buy it, because the only thing I am getting is a different platform.
Also you need to think about that people who do buy now on Steam do not have to buy the game twice to get it on 2 (or even 3) platforms. They pay the same 25 bucks I paid, and get more stuff. To get "even" with the, I have to pay 50 bucks and then I get stuff they get for 40 bucks.
It's just not something I would have expected from obsidian. I kickstarted PoE, PoE2 and Tyranny (PoE and Tyranny DO run on all platforms with one purchase by the way). But this "business model" just makes me feel like was wrong giving Obsidian my money early, since I do get quantifiably less than someone who is paying the same money now.
/edit: Also I personally do not care about the things in the obsidian ultimate edition. Steam would just be another platform for me to play on. I will not spend 25 bucks on that.