Some of us just don't know what they are or how to use them. I guarantee I'll be forming another study group some time in the future on the other topics you mentioned if they are as broad in application as you say. :)
In my mind, neural networks should only be used when you're trying to model actual biological systems. Otherwise, one should always use a proper model - since it actually gives insight into what's going on with the system, instead of just being a magic black box. Of course, notice that all commonly used ANN topologies have nothing to do with biology - feed forward, hopfield nets, kohonen maps etc. They have barely any resemblance to how actual neurons behave. Basically, they are just heuristics with a cool sounding name.