The following are neither TPR's views nor held by some UK pension actuaries. Everyone is seeking security for members, separating pensions loss from possible jobs loss. However, the sponsors also need some security against needing to account for liabilities too cautiously.
The principal purpose should be to cover benefits as they arise over time, rather than all at once. Reflecting how insurance reserves are set and that profits are sought, wind-up is very expensive. While it may sometimes be appropriate, why should the sponsor be forced to crystallise capital (deficit repair) in advance when it is not necessary?
The replacement of discretion, which acted as a buffer, by guarantees, which are generally not well understood by sponsors or members, has been a huge problem. This all appears to stem from the actuarial adoption of financial economics for DB pension funding purposes.