@dumbdonkey, that seemed to have nothing to do with rooftopping.
Rooftopping, as long as people are not damaging property, seems fairly innoculous. I suspect that most people do it are in it for the urban exploration, especially in a city like HK where the tops of buildings are pretty interesting and give great views. Certainly, the people I've known to have done it are just interested to see what's out there and to take good skyline photos.
I'd suspect that the media only pays attention to the idiot/daredevil element.
Personally, if I had to choose between roadbiking on HK Island (I bring this up because I cycle, and cannot fathom why people ride on the Island) or trying to get access rooftops, the second seems the far safer option.