In your original post you assumed that private schools had better teacher morale - why? In my DDs independent school lots of the teachers were totally pi__ed off with the new Head and left pretty quickly. They are taking money from parents and they have to perform!! To a high standard in many cases. Just because a school may have smaller classes, do not assume teachers are happier!
I think some teachers do not find it easy to manage their time. I would also be unhappy if the demands of SLT were over-bearing and counter-productive. As a Governor and we always consider the work/life balance of our teachers. However, if a teacher is disorganised and does not get round to marking in a timely and effective manner, in accordance with our policy, and everyone else does, then this is something the Head will rightly discuss at their pay review. The Head will, however, look at why there might be a problem and how it can be resoloved. We want the best for the children and we also want the staff to enjoy working at the school. We have senior staff on job share contracts. The SLT and Governors rigourously look at the quality of teaching and progress of the children but why should the children be short-changed in their education by ineffective staff? We lose very few teachers. We do not have a problem recruiting teachers.
As in all walks of life, some SLTs are better at managing staff than others. However, most schools internally discuss and formulate marking policies, behaviour policies, etc. They are not just imposed from above, and in our school the staff have ownership of the policies. This is driven by all of us wanting our children to do well and make very good progress, not just Ofsted.
The new Ofsted framework is very clear about what they want. I suggest teachers take some time to read it and maybe have some training on the framework. Then it will not be possible for schools to blame Ofsted for the culture in school - because the teachers will know better.