One of the main difference between standard approach and agile way is in the way the work assignment is organized and tracked. There is no responsibility for module or any given part of the code, nor ms project with task assignment to concrete person which can be tracked and be a basis for employee evaluation, bonuses or promotion.
Maybe it is a little bit to harsh, but in general it is an approach based on fear or greed.

On the other hand, agile promotes work tracking on team level, which means that individual is a little bit hidden - no direct personal responsibility.
Main element of motivation, comes from peer pressure, so someone cannot just not do anything because it hurts the team. But when whole team is demotivated then peer pressure suddenly disappears. Since work is tracked on team level and nobody is working in the team then responsibility is blurred.