SW Coastline- can farming survive here?

One of the wonders of our British landscape is our coastline. Leaving aside its impact on our history as an island nation; from Romans to William the Conqueror; from smugglers to launching the D Day armada; it is staggering in its beauty. Walking the stretch from Prawle point to Salcombe, I was struck by several thoughts.
The scenery is dramatic but so also is the birdlife and the plantlife. The song of the skylark is uplifting here but is rarer elsewhere these days. Plants thrive in the muddle and disorder of the climax vegetation of the cliff edge beyond the reach of the fertiliser, pesticides and herbicides; products that are so necessary for profitable farming but which create uniformity and lack of diversity in the landscape.
People walking the path seem universally friendly. Smiles and waves (the human kind!) suggest that the experience is doing them good both mentally and physically. We were also made welcome by two volunteers from the National Coastwatch Institution at Prawle Point. This wonderful organisation, made up entirely of volunteers, plays a vital role for those in trouble at sea.
The other organisation that deserves credit too in this area is the National Trust under whose stewardship much of the land falls. Car parks are provided at both ends of the route and one is reassured that the coastline is in good hands.
People seem happy to follow the path. We certainly were with a party of nine including two dogs. The need for swathes of extra land as 'spreading room' suggested by Natural England as part of the coastal access debate seems unnecessary.
Yet there are some downsides too. The popularity of the route and the numbers of walkers is leading to erosion of the path. This erosion is severe in places.
 Most people use cars to access the path. Car parks are needed. A similar dependence on the car is often used as a reason why planners turn down diversification applications in rural areas.
The much vaunted benefits to farmers and landowners whose property adjoins the path is a bit of a myth too. We walked for some 5 miles and not once did we see an opportunity for them to add value from the visitors crossing their land until we reached Salcombe. The National Trust is a charity and can afford to take a lower return; private owners do not often have that option.
I was particularly interested also to note the agriculture. There is evidence near Prawle Point of ancient field systems with field boundaries marked by flat stone slabs set on edge and, from the C18th until the 1960s vegetable production using the abundant seaweed fertiliser. For modern farming however it is uneconomic with tiny fields, poor access and fences undercut by the retreating coastline. Left to the free market, I doubt that it would continue yet we know the importance of grazing to the maintenance of biodiversity and where it doesn't happen topping, flailing and rolling is needed to control the bracken and gorse and this, of course, costs money.
Surely another example of the wider benefits from agriculture beyond simply food production and the need to find a way to fund it...