I came across this article by Colin Harris the other day in the TES. It's ace. He's a head who knows that we're not going to create tomorrow's school leaders if we inculcate teachers into a culture of mistrust. 'Monitoring them to death', as he puts it, does not harness their energy, enthusiasm or creativity. If we are to attract dynamic, inspirational teachers into leadership roles, we need to create a space in which they can experiment, research, fail, improve and develop. The resilience needed for this can only be created within a culture of "praise, guidance and trust".
I'd take the argument one stage further: why not grow this culture of trust and guidance for all teachers, not just the leaders of tomorrow? In fact, why stop at teachers - why not develop a trusting culture for all school staff? For children, even?