Gingernuts, the nursery operates as a sole trader. This sole trader resides at the property. I believe that if the owner decided to sell the business, she would also have to move out, which means the planning permission would be revoked.

Your point seems to be what "could" happen, rather than what is happening. If the nursery loses the case, and is forced to sell the property, the neighbours "could" equally find themselves next to some noisy new neighbours, with 3 teenage children, each having a drum kit, electric guitar and keyboard. Alternatively, they "could" find themselves next to a GP surgery - which is allowed under the terms of the covenant, and could cause a lot more nuisance.

You mentioned perspective. I think this is missing from the objectors side.. They need to look at what is actually happening, and enjoy the peace and quiet, rather than spending their lives worrying about what could happen if and when a whole series of events occur that are each very unlikely.