Building a team based on trust is difficult because in the course of career advancement and education, most successful people learn to be competitive with their peers, and protective of their reputations. It is a challenge for them to turn those instincts off for the good of the team.
The failure to do this, however, is great. Teams that lack trust waste inordinate amounts of time and energy managing their behaviors and interactions within the group. they tend to dread team meetings, and are reluctant to take risks in asking for or offering assistance to others. As a result, morale on teams lacking trust is usually low, and unwanted turnover is high.