Yeah, it was pretty rough to watch. But it served a particular purpose within the context of the story.
I'll try not to spoil things beyond what we've already said here, and the basics of what you likely read about how the Great Society ends. But for a while, one of the big questions people (ie., fans) were asking was "If two realities are colliding, why not work with the other earth's heroes to find a solution?"
The Great Society, and what eventually happens with them, is the answer. Working together is all well and good, until you realize that there's very, very little time to do anything, and if nothing is done the result is two entire universes dying, whereas if one earth is destroyed, both universes get to live. It raises the question of how far you're willing to go, and if a few billion lives are worth the cost of the countless lives across two realities.
The Great Society are clearly meant to be the League, and they're written as being much better people than the Illuminati/New Avengers, or any of the other characters we've seen from other worlds. If there was ever a version of earth where the heroes would be willing to work with the Marvel crew to find a solution, the Society was it. But they only have a few hours to do anything, and when the Society learns that the Illuminati are already prepared to take drastic action, the burgeoning trust falls apart and things spiral out of control.