As a Totally neutral observer, your team basically beat themselves. Taking dumb penalties negated any chance for them to make a comeback, and those players who took those penalties should be made to apologize to their teammates, who were genuinely trying.
If the coach doesn't hold them accountable, then the team captain, and the players wearing the letters should. Accountability can become a good habit to cultivate, and a team that encourages and promotes that culture is far more likely to bond and become successful.