I agree that people should not feed them as this will make them more trusting of humans and encourages them to over breed. If left alone their population will find its own natural level.
Foxes are a valid part of the eco system and help keep down the rat population as well as feeding on already dead animals.
Yes, they do make a mess when they scatter the content of discarded plastic sacks and the remains of take away meals that litter our streets, but that is caused by thoughtless humans that do not dispose of their waste responsibly.
Foxes have as much right to live on this planet as us humans and probably more in some cases.