Frankly, your comparison doesn't make a lot of sense even if you do completely ignore the word 'communism' and make a point of referring to all communist, Maoist, Marxist regimes exclusively by the word 'socialist' so as to taint the word as much as you possibly can. Even then, you still can't ignore that before, during and after those horrible regimes, the word also described and describes peaceful and democratic parties in many, many countries around the world.

Whereas for fascism, well, there's not a whole lot to associate it with other than Italy and then the other Axis powers. There might have been, if history had gone differently - Oswald Mosley's fascist party in 1930s Britain had abhorrent elements like anti-semitism, but wasn't necessarily anti-democratic. But WW2 pretty much tainted the name for good, before it had much of a chance to develop. Except I guess in Italy, where the associations were more complicated and where Mussolini's granddaughter has a seat in the European Parliament, not a bit ashamed of her last name.