I think this will be my final post on this topic.
It has been interesting to read everyone's comments and views. Thank you.
Back in the 1970's long before the Land Reform Act and other legislation established rights of access to open land (and no doubt before many readers of this were born) I walked and camped in the hills of Scotland, Wales and England.
At that time just being on someone else's land without permission would not necessarily have been a trespass, however if while on that land one did something that damaged the land or interfered with the owners rights then a trespass would have been committed. The probability of being caught was minimal and any court action unlikely, though in some places one might be shot at.
But this is not the main point.
The fact is that back then if I and the others who also walked the hills left evidence of our presence then it was more likely that the land owner(s) would do something to prevent the likes of us from going on their land.
By not leaving a trace of my presence meant that I would ensure my fellow walkers and campers would have the opportunity to do as I had done and walk and camp unhindered.
In these circumstances
awareness of being on someone else's land and also
respecting one's fellow walkers and campers by not doing anything that might compromise their easy access to the hills meant that no one left evidence of their presence in the hills and we all enjoyed the same uncluttered landscape.
Since the access legislation came into effect more damage has been done and more evidence of peoples presence has been left than in all the decades we were "not supposed to be there".
In some ways the "good old days" were better.