First the stated Topic.
I hear this same complaint all the time and comiserate with it.
Several factors that contribute to it:
1. Scoutmaster with no youth experience as a scout or in a troop where this was the example he saw - if you have no example and poor training you do what you know and are comfortable with.
2. Basic Type A personality that leads to control issues
3. Terrible District Executives and Commisioners that focus on Troop creation and self promotion vs. Mentoring to achieve well run Troops
4. Backlash from a previous SM who thought Boy led meant hands off and