i don't know what it is, but I always disliked offline progression in any idle game. Whenever I come back to a game and see big gains, I don't feel fulfilled, but disappointed. Maybe I enjoy the challenge of 'manual' progression. I'm not sure.
I've had a short list of idle games that allow disabling offline progression (or don't have it altogether.) Such as Exponential Idle, Antimatter Dimensions, Idle Research, Orb of Creation, Increlution... this game was on that list, too, until the update.
I apologize if I sound coarse, I don't mean to. I know I am in the minority, and possibly even alone. But, I can't help the feeling of disappointment.