I think maybe its a good thing for the consultants who are asked to resign.
First, the job they do currently maybe is not a good fit with his skills. Let's suppose that someone works in a famous consulting firm now, when he is asked to resign, other small consulting firms may need him. And investment banks (and many other companies) who are looking for people with consulting skills may need him.
Second, the experience in working in a big consulting firm is good for his CV, and will open up more opportunities than a graduate.
Also, I think consulting is a high risk industry because it has a high turnover rate. A critical reason is the "up or out" policy, but it may be risky for other reasons as well.