Humans are anti-sheep.
Someone will form a group to rebel against any given issue, whether important or banal. Surely, even early pre-humans had traditionalists keeping the tribe alive, and anti-traditionalists thinking the old ways were dumb and looking for new ways to do things. "This spicy rotten fruit juice good." "Me tired of nomadry. Me stay here, tend plants, make much-much spicy rotten fruit juice." "Maybe the Earth is round." "I think dried cow blood can protect me from disease." "We should use our nuclear weapons." "Everything is a coverup, the Earth is flat." "Maybe injecting dried cow blood causes autism." "Things are/aren't fine as they are."
Perhaps this is a unique quirk of Humanity that has allowed rapid technological advancement1. Or perhaps it is a common prerequisite for advanced civilizations. Will this be what lets us overcome the Great Filter and become an interstellar species, or will it all be destroyed by a group of angry space-luddites weaponizing their standardized anti-matter reactors?
1 - I like to think about China through the ages at this point. A country is not a great data point for extrapolating how aliens without the constant off-group break-offs might advance, but it's the closest real point I can think of. They were a giant ocean of stability for millennia, with everything they theoretically needed to advance, and perhaps rule the world. But they didn't use their gunpowder to build guns. They scuttled their navy of giant ships and shipyards because their political power was focused into one singular point, without anti-sheep continuing the fleet. They were too stable, and had little reason to shake up the status quo.