The way you lump all sorts of different things under the fascist rubric renders you politically useless. Equating social democracy with fascism is the the political equivalent of heading a snooker ball; while it could be entertaining to watch it is something you've been doing rather too much of.
Louis MacNeice
Do you think it is useless to lump all different kinds of supernatural faiths under the rubric of religion? By the definition of religion as a systematic belief in the supernatural, the vast majority of the Earth's population (>95%) is religious. Does this make religion a useless concept? Is religion an "atheist-centric" concept? I would think not. Religion is a useful concept even for those who ARE religious. By the same token fascism is also a very useful concept, even for those who ARE fascists because there are different kind of fascisms: islamofascism, socialist fascism, christian fascism, feminist fascism, ecofascism, nationalistic fascism etc. A socialist fascist may be very concerned about islamofascists or christian fascists gaining control over society. Indeed, the term "fascism" is analogous to religion in many ways: most religious people think that their OWN religion is obviously true and fantastic, whereas most religious people regard OTHER religions as complete bollocks and they cannot understand how anyone could be so stupid as to believe in such shite. Only atheists think that religion as such is crap.
By the same token most fascists think that their OWN form of fascism is obviously true and fantastic and they have zero problems forcing everyone to bend to it, whereas most fascists regard OTHER forms of fascism with horror. They dread the thought of living under another form of fascism because the thought of being forced to abide to someone else's belief system is fundamentally repulsive to humans. And by the same token only liberals think that fascism as such is crap. They dread ALL forms of fascism equally much.
Thus liberalism is highly analogous to atheism. (And liberals are typically also atheists) Indeed, religion and fascism are related. Religion is a form of collectivism, and fascism is FORCED collectivism.
Just like there only exists one form of atheism there only exists one form of non-fascism, and that is liberalism. Liberalism is the only political philosophy which allows all people to live out their belief system so long as they are peaceful. In a liberal society you are allowed to live as a socialist, but in a socialist society you are not allowed to live as a liberal. That is the hallmark of fascism vs liberalism.
To an objective third party it would be absolutely obvious why this definition of fascism is useful, but I know why you don't like it and that is because you do not want to acknowledge that you have something very fundamental in common with Hitler, Mussolini, Stalin, Mao, Pol Pot, Ahmadinejad, Barre, Marcos, Kim Jong Il. You don't like the idea of being placed in the same category because it makes you question whether you might be the baddies.