Section 35 isn't being used to stop people specifically feeding the homeless though, is it? It's been used to disperse some anti social individuals (over 2 years ago).
That argus article is well over 2 years old. Sec 35 is around moving anti social behaviour from an area - given at that time there were a huge number of calls from shop keepers and residents around such behaviour it doesn't seem such a poor use of those powers. Feeding the homeless isn't illegal.