To explain a little from what little I know about the problems fruit bats can cause:
There was a similar issue with fruit bats some years ago in a town called Maclean in northern NSW the bats roosting sight was near a school and this often depending on wind direction etc made the school close on a regular basis, I also think it was in some cases making kids sick, and being really distracting for the kids trying to learn for both noise and worse the smell (fruit bats REALLY stink!!) lastly the fruit bats were causing the death of a lot of trees at thier roosting sight which I think (could be wrong) was a small patch of remnant rainforest.
Hopefully that sort of explains why the council wants to deter the bats from roosting in the park, I'd guess if they didn't smell and didn't pose a health risk (which I'm not sure but they may, certainly a rabies like virus hedra?? has been contracted from fruit bats) and there wasn't the prospect of them killing the parks trees they wouldn't really have a problem with the fruit bats.
Generally in my experience Australia and Australians aren't against bats but I also think we have a lot less exposure to bats than some of the US, for example I've not heard of bats roosting in houses or under bridges here but we certainly have bats in caves and laws and access restrictions to protect them during hybernation and breeding. Fruit bats are the only bats I know of that have caused any problems for the general community and this would typically be in the tropics or sub-tropics, which is curious because I thought Singleton was a bit far south for fruit bats.
other info:
http://www.abc.net.au/gardening/stories/s727782.htm (says flying foxes used to range as far south as Sydney which was news to me) (<edit> reading one of the articles it says there is a new colony in Cabramatta which is near Sydney, shows how little I know
)
http://sres-associated.anu.edu.au/batatlas/maclean.html About the problems in Maclean and the rainforest reserve.
http://sres-associated.anu.edu.au/batatlas/index.html A general fruit bat page for Australia...
PS: Personally I don't support culling, there has to be better solutions and a balance sought, but I can see the problems a fruit bat colony might cause so this isn't just people being ignorant and wanting to kill bats for the sake of it.