List of thought-terminating clichés:
"It is what it is."
"That's just the way it is."
"Everything happens for a reason."
"Let's agree to disagree."
"It'll all work out."
"You're overreacting."
"Calm...
They work well and can be useful on a personal, intimate level by easing momentary tension (the verbal equivalent of taking a deep breath and evaluating a situation), but can be dangerous like you described when scaled to societal level.