One Devil's tool against cooperation is reminding people that cooperation is cultish, and if they cooperate, they are sheep.

But there is a big exception! If you work for a corporation, then you are expected to be a team player, and you have to participate in various team-building activities, which are like cult activities, just a bit less effective. You are expected to be a sheep, if you are asked to be one, and to enjoy it. -- It's just somehow wrong to use the same winning strategy outside the corporation, for yourself or your friends.

So we get the interesting result that most people are willing to cooperate if it is for someone else's benefit, but have an aversion against cooperation for their own. If I tried to brainwash people to become obedient masses, I would be proud to achieve this.

This said, I am not sure what exactly caused this. It could be a natural result of thousand small-scale interactions; people winning locally by undermining their nearest competitors' agency, and losing globally by poluting the common meme-space. And the people who overcome this and become able to optimize for their own benefit probably find it much easier to find themselves followers than peers; thus they get out of the system, but don't change the system.