I read an article on this subject in one of the tabloids last week. It was, I thought, a bit thin on detail and had the feel of a column filler.
I did the last of my four crossings to date in August 2013 so it is a while ago but I did not notice any massive environmental damage overall and certainly none that, of itself, made the walk more unsafe than it could be ( like any upland walk) in bad weather.
The Nine Standards section may be a slight exception as the peat bog does look rather dog eared for a couple of miles south and east of the stones. The Pennine Way solution would be flag stones. The PW bog is much more extensive than Nine Standards and in a way the C2C would lose a moderately challenging part if flags were laid ( and it has less than the PW to my mind).
I quite like the fact that the C2C has few formal waymarks (although the impromptu Farmers versions are of variable quality). Obviously this would change with NT status.
Has it really deteriorated lately or is it just a bit of hype?
John