Judges implement the law though, so if the contract says "no business use" and this was made clear at the time of purchase -- eg by having business level accounts -- then what can the judge do? It's for the legislators to legislate, not the judges (under English law (UK), common law and equity aside).

Actual, I might be wrong here with how contact law is handled ... anyone?

A related consideration: when we moved into our terraced house the land was under leasehold and the lease specified 'no business use'. We bought the freehold some time back, but I've often wondered what my position might otherwise have been. Presumably breech of the lease conditions would be a tort against the landlord and so I'd have been fine as long as they didn't sue.