Teamwork is a constant balancing act between self-interest and group interest.
Self-deception operates both at the level of the individual mind, and in the collective awareness of the group. To belong to a group of any sort, the tacit price of membership is to agree not to notice one's own feelings of uneasiness and misgiving, and certainly not to question anything that challenges the group's way of doing things.
A good team is a great place to be, exciting, stimulating, supportive, successful. A bad team is horrible, a sort of human prison.