You've revised the question in comments; you're not asking why people opposed Communism, you're asking why they opposed it more than Fascism (dictators)
The difference is twofold - first in the claims they made and second in the cultures where they took root.
What claims did Communism make?
Communism advocated worldwide revolution, the abolition of private property and the establishment of a new world order. (pick your own source - they all make me sick to the stomach to read)
According to the communists, only the laboring class would rise; all others would fall (and probably fall to the knife). Take a quick look around you - are you willing to bet your family's life that you're one of the elect? Are you completely sure that there isn't someone poorer than you who will claim that you are bourgeois? (Hint: if you're using the internet, I can guarantee that there is a class of people who will happily denounce you, and seize your property as their own.)
Communists offered class solidarity to a world that wasn't accustomed to thinking in terms of classes. (I yearn for those halcyon days when we could actually think about a problem before first assigning blame to the bourgeois). You would ultimately be united with people who shared your class interest, but you had to learn communism before you understood your class interest. And of course if you didn't understand your class interest, you were a counter-revolutionary and should be punished. Is there anyone who wants to admit that they don't share their class interest? Trains to the labor camps form on the left.
Communists rejected religion and pretty much all traditions. If there was something you liked about your childhood - a holiday, a meal, the notion of a birthday present? that was counterrevolutionary and must be suppressed by force. Everything you remember as pleasant must be replaced by communism. You have no immortal soul, there is no God. If you believe there is a god, the train to the labor camp starts on the left. If your parents are religious, the state will ship them off to a labor camp; all you need to do is betray them to the state. Or if you have some loyalty higher than the state, the train to the labor camp begins on the left.
The future is filled with struggle but the Party will ensure that in the end we will triumph. Not in your lifetime - you need to give up all your wealth in solidarity and struggle like an animal until you die. But someday, someone will have a glorious worker's paradise.
What claims did Fascists make?
Mussolini and Hitler offered to bring order, to bring pride to the nations, to cultivate and raise up the people to their true nature. They promised to keep order, to keep people safe, to enforce the law and make the trains run on time.
There is also a cultural context. Germany and Italy needed hope, and their culture was receptive to ideologies that provided hope. I'm not as familiar with Italian Fascism, but remember that German Fascism was in part a reaction to French Liberalism. France conquered Europe and imposed "liberalism" on the conquered people. (the fact that the liberalism looked a lot like autocracy is just a detail). Germany explored alternatives to Napoleonic Liberalism - alternatives in which it was possible to be proud to be a German.
BBC History had a very good article on Italian reactions to Mussolini a couple of years ago - I find it nearly impossible to cite articles from BBC history, but if you search their website you should be able to find it.
Dictators offered racial/ethnic solidarity - you would be united with people like you. People like your neighbors and friends. The power of the nation united would transform you.
Tradition was good - the traditions, habits, cultures and religion of your parents are part of what makes our nation great - you should be proud of these traditions. The future is so bright we've got to wear shades!
I'm not defending fascism; both were evil, anti-liberal ideologies. But I can't see how anyone who is not mainlining hallucinogenics could choose Communism.
