If the employee is good, why would that matter?
And if they're bad, why are we defending bad employees?
I never said the employee was bad, I was inferring that there's a lot of competition for some jobs in light of large amounts of redundancies being made in recent years, so some employers may want to take advantage of the fact in this scenario.
Sorry, but giving up your employment rights is plain barmy. I can see where the idea comes from but it's just open to abuse IMO. Would a constructive dismissal claim be valid under this waiver, for example? Things can change rapidly at work, especially when costs are involved.