Aye, well it isn't as if the landowners aren't getting oodles is it?
http://www.defra.gov.uk/erdp/schemes/esas/payrates/stg1rate.htm#pennine

but the archaeological element of the protection isn't very prominent or specific:

Resulting environmental benefits have included:-
improved numbers of wading birds in lowland wet grassland;
protection and improvement of species rich grassland on the chalkdowns and in hay meadows;
landscape improvements from better management of features such as hedges and dry stone walls and from conversion of arable to grassland;
protection of historic features, such as ancient field systems.

An archaeologist employed by Natural England on a metal detecting forum assured the 'eroes that he had "pulled out all the stops" to ensure a rally could be held on the Durobrivae Roman site in the teeth of opposition by the County Archaeos, local archie societies and English Heritage. The whole thing was televised (Water Newton, on The One Show) as a triumph of co-operation.

There's protection on paper. Then there's the real world where officials adopt completely perverse or neglectful positions while taking our money and where people that feel like it then take what they want as if they had a moral right. In both cases it's stealing, whichever way it's dressed up, as we both know. But we're merely the public, the owners and the paymasters and can be safely ignored...