Imagine the dumbest person you've ever met. Now imagine they couldn't find a job, or have a court ordered decision between jail or military service. That's easily 10-15% of enlisted personnel.

Over time, people with options who want to focus on family life or are sick of the bullshit will leave for greener pastures. This leaves a vacuum where the qualified folks leaving get filled by time in rate lifers. A significant number of folks in leadership positions are there because they've been around longer then anyone else available at the time.

So yeah, it can be pretty bad.