Epic monsters

So I have been wondering to myself lately why it is that baron, rift herald, and dragon aren't hostile monsters. I can understand that many of the camps are neutral because they are just chilling in the jungle, however Baron, Dragon and Rift Herald all have their own "territory" so it doesn't make sense that they are neutral. They should want to keep anything and everything out of their turf so maybe they should auto agro on anyone or anything that enters the pits. Just my thoughts. Also I was wondering why they don't throw wards out of their area too. I was just thinking that they'd like their peace and would keep anything out of their area that would affect that peace.