Many of the Megachurches do not apply Harvard Business Principles, but simply apply good management, or good stewardship.
Others succeed despite themselves.
You're trying to paint with too broad a brush. Megachurches are not at all from the same mold. Mine is very tight doctrine:
Beginning sentence from a sermon two weeks ago:
"The trouble with most marriages is..........the husband".
He asked the husbands to stand, which we did, and said "This sermon is for you. For some of you this is the last time we will see you here".
And then he laid into us.
I was under the impression that the church was to forgive people for their sins. If the pastor only laid into the husbands and provided no absolution, you're right, I wouldn't go back. Of course, I probably wouldn't have been there in the first place. Was there any Gospel?
It isn't as popular as "The Purpose Driven Church," but it should be read by every church leader who is tempted to go the megachurch route, if for no other reason than to be conscious of the pitfalls.