Is that the real reason why those companies are hired? Judging by the comments here I wonder if there are any success stories at all.
They love consultancies. It's a total roll of the dice if their projects are successful or not. I've seen it go both ways.
I work for a more technical focused niche consulting firm, and one of our specialties is large IT implementation project recovery. We are extremely successful, but it's dirty work that isn't super advertised.