hmmm lets see...you came into MY thread and clearly want to argue back and forth (apparently for the rest of our lives) about why changes were made to a game and how stupid I apparently am for not agreeing with you when I don't care if the changes where made or not. I simply would have like the simple option of whether to allow/accept the update or continue to play my single player game without changes that were made for other peoples preferred gameplay. This would have made everyone happy. You would have gotten the changes you clearly feel were "badly needed" and could play the game the way you want to play. And I could have kept the game I downloaded and was enjoying. Your gameplay would not have affected my gameplay in any way, shape or form and my gameplay would not have affected your game play in any way shape or form.
I'm not even going to bother with your other points, because you chief rebuttal is "NO, YOU MISS THE POINT" which isn't really a good argument for anything. The reality is you don't need to agree with me, the facts you're trying so hard to ignore speak for themselves. The changes were badly needed for the sake of gameplay, you don't understand that because you haven't been playing that long. Instead you prefer to argue the semantics of "gamebreaking" in a context which is entirely irrelevant to game balance.
I'm sorry this change irreparably damaged your experience, perhaps they'd give you a refund if you asked. That's between you and steam. Ironclad was pretty clear in the patch notes that the update would break savegames. Your issue really is with steam in that regard for auto updating. Realistically, you have complete control over the auto-update features, so it's your own fault.