Brad deLong has a great discussion of the difference between quants and schmoozers (or specialists and generalists, in my terms) in the investment bank community. Any young consultant who wonders why the old farts on the golf courses are paid so much should read it – for one thing (not mentioned by Brad) they know the capabilities of their own company and which deals to walk away from.
The greatest danger to a consulting company (or investment bank, I presume) is the young salesman who doesn’t know what is hard and what isn’t. The old farts are there because they have tacit knowledge on what they can commit the company to, and at what price.