Since I have never used the path in question, I don't have a dog in this fight and since I am up north for the summer don't have all the facts. This being said, I haven't noticed, in the posts on this subject, a mention of the possibility that residents, if they have used the path for more than 20 years (I don't know if this is the case), may have already acquired what is called a prescriptive easement. For an explanation:
FE108/FE108: Handbook of Florida Fence and Property Law: Easements and Rights of Way
It is something that the folks who are addressing this issue may want to consider. The fear of residents' acquiring, or maybe already having acquired, such an easement may have been one of the motivating factors causing the Developer to erect the wall.