The phrase starts with that but includes a lot more because fascism crops up during times of uncertainty and instability. So too does other radical ideas. The definition I put forward is a universal one. Defining an ideology as being against something else is not an ideology. It would be no better than saying that anarchists are defined as being antifascist. It simply shows you don’t understand what they believe.
If you don’t understand what they believe, you cannot understand why it is bad. Suddenly you are justifying the invasions of sovereign countries on ethnic lines and here we are.