Yes it must be used always so the money can circulate. They are afraid of something else it is the lack of knowledge that scares them. Bitcoin might be a little hard to learn but while using it and asking,reading news and more you will get used to it.
It's not just them lacking knowledge - it's the fact that at the moment Bitcoin is inherently more difficult to use in real world scenarios than fiat - so while Bitcoin may have benefits those benefits presently do not tip the scales enough. This is especially true in less developed countries and basically all other countries aside from the US where there is less infrastructure in place to support Bitcoin payments.