>The "reasons" given look a bit forced to me. Damage to a drystone wall? Why not construct a style and a pathway then...<

Um. I'm sure that last time I went there I entered the field through a gate. By a tiny excuse for a lay-by.
There isn't really any safe place to park on this road apart from here as it's a 'fast' road, i.e. people drive like maniacs on it. And it's on the brow of a hill. This entrance really is the obvious place to get access to the field.

So, I'm a bit perplexed why people are having to climb over walls to get there.

Oh, sorry - missed the point. I shouldn't be going there at all.

I got lost. Again.