Extreme ownership is a great book with lots of sound advice. However, I don't find the approach flawless at all.
These guys had the benefit of being leaders in an organization that is set up to rapidly show you the door if you under-perform. Furthermore, everyone that's on a SEAL team desperately wants to be there. To some extent, extreme ownership falls apart in a regular, non-combat focused military unit and also in many civilian organizations.
If you're a Soldier, the military's authority is an illusion. Don't assume that my next statement means that punishment is my first tool for attempting to remedy under-performance, but at some point with some people it becomes necessary. In those extreme cases, even that's not effective because of the way the military operates. Half of the punishments for being lazy/ineffective at your job only work if you voluntarily participate in being a part of the military. Examples: exercise as punishment only works when people choose to exercise. Putting people on punitive details like picking cigarettes up and raking lines in sand for 12 hours a day only work if the people voluntarily do the work. Some people don't show up at all and some only show up to laugh in your face and tell you to go fuck yourself in front of your superiors.
Even the punishments that don't require participation still do require voluntary participation in a way. In the military if you give someone nonjudicial punishment, typically they lose half of their pay for a month or so, and in extreme cases they'll get permanently demoted in addition to that. So you take their money away. However, for the kind of people that aren't doing their job and don't intend to, that doesn't really matter much. You are giving them 3 meals a day and a place to stay. You don't have the power to take that away from them without kicking them out of the military, which in a regular unit often takes well over a year and always requires leadership support, which may not exist given the fact that most units are operating with less people than they need.
It may be hard to see where I'm going, but my point is this. There are people in the military that don't intend to do their jobs. All of us have run into the same type of people in a civilian workplace. You can't inspire them because they don't want to be inspired. You can't lead them to do what they are supposed to do because not doing it is the only control they feel they have over their lives. The only viable option for some people is to remove them or ignore them and spend your precious time on the people that are getting the mission accomplished. In many cases, the latter is your only option.
I'm no Jocko Willink or Leif Babin in terms of being a Soldier or a leader. However, I spent almost 2 decades in the military and helped numerous Soldiers go from under-performing to be very successful. I learned that in some cases, usually when someone regrets joining the military, that you just have to move on. Sometimes, in spite of what extreme ownership claims, things really aren't your fault. As a leader, most things are your fault though, so I do agree with the overall message even if extreme ownership isn't a magic bullet.
Similar people exist in a civilian context.
Hopefully people won't read the above and assume that I avoid responsibility for my mistakes. On the contrary, I was known in the military and in my civilian job as a person that was honest and forthcoming almost to a fault.