Well, well Roy! Everyone loved it - perhaps because it was escapism to some ethereal version of England which mainly exists in those rare transitory moments of dewy cobwebs as the sun comes up.

I like to think the savvy Mackenzie Crook did a bit of research, maybe even looked at websites such as TMA (the rainbow at the end) and realised a comedy about metal detecting had only a limited life span. In the end their 'pot of gold' came to them by a fairy-tale fluke - they pointedly didn't dig it up. The final series spoke far more about conservation - bats, trees, hedgehogs and an old run down property in need of renovation rather than a pristine, sterile new build.
Perhaps the message is metal detectorists are looking for 'treasure' in the wrong place.