Here is my top 10 list based on my observations over the years in Agile Teams. As always, comments / feedback are very welcome.
#9 Fear of Failure.
#8 Prefer structure and predictability over adaptability and spontaneity.
#7 Believing in team of specialists are more efficient than generalists.
#6 No Retrospectives (lack Continuous Improvement culture).
#5 Deadlines are set by Managers.
#4 Believing in Status Quo is safer and more predictable.
#3 Reward individual’s accomplishment instead of team’s accomplishment.
#2 Team’s goals and objectives unclear.
#1 Managers / Leaders not willing to relinquish control.