One of the appeals of Lean is its framework to describe, from a high altitude, how a process or collection of processes should operate. It appeals to readers.
To sell books on Lean, one needs only to tell the stories of how those processes should operate. It appeals to authors.
Understanding the books and the stories makes one literate on Lean, able to use the lingo, able to fly over a situation and offer advice. It appelas to senior executives.
Implementation, however, is the truly hard work of Lean. By definition, implementation is at a low altitude, encompassing detail. It's hard to write interesting books about the boring, long grind of implementation.
And the true leader accepts this, buckles down, and implements anyway.
The leader does the hard work.
The one who does the hard work is the true leader.