I enjoy reading books by theorists. Their views on society and cultural changes are extremely helpful.
Yet here's where we need to be careful. Beware of theorists posing as practitioners. I have no time for a theorist telling me how to run Calvary Fellowship. Why? Because they've never done it.
Honestly, I sick of guys writing books about how to "do church" who have never actually done it. Or, they pastored a church, left, and then wrote a book about how everything needs to be different.
With all due respect, It would be a much greater service to the body of Christ if they simply showed us what to do by modeling it for us.
Unfortunately, that's a lot harder than writing. (Rant over)