It's because fascism is shorter, and sounds scarier than authoritarianism.
Even though communism always results in authoritarianism, depending on who you ask regarding what "real" communism is they will claim that they aren't inclusive of each other.
If you want normies to stop calling the left fascists, you need to find a shorter and more effective term to describe their actions. The general population isn't mentally equipped to use words as long as authoritarianism.
Alternatively, and perhaps to more effect we should simply abandon the terms fascism and socialism. Nationalism and traditionalism are a lot less loaded, and focus on the positives of what we want to accomplish, without the baggage. Helps older conservatives who want to claim that national socialism and fascism are leftist ideologies make the transition away from the republican party without soiling themselves in fear.
Keep in mind that pretty much every paleo-con comes from a john birch society-esque view of the political spectrum that lumps national socialists in with communism. They don't differentiate based on policy, and to some extent I would sympathize with their views during non-crisis times. All political power is prone to corruption over time. The most effective way to push what we desire, is to refer to national socialism like Rockwell did. Push the idea that it supports small government, but the government that does exist shouldn't be neutered. That which the state controls should be streamlined, but all powerful.
I know there are a lot of disagreements so far as what sectors of our economy would be under state control, and what would be free market, but a small government approach makes for a better argument. When a lot of people refer to small government, or restrained government, or libertarianism, they are mostly concerned with their individual lives. They don't care as much about regulations on corporate entities. They want to be able to build their own shed without government interference. Or they don't want to have to wear seat belts or helmets. Or maybe even open their own woodworking business or something, without the red tape. So long as you can express a desire to leave people alone at that level, most people wouldn't actually give a shit about you forcing the CEO of Walmart to pay the workers more or something. The resistance to that from the right is philosophical in nature, because they also suffer from government coercion. If you stop the coercion of the little people, they won't feel the necessity to vote to protect themselves and the big people on a philosophical level. They will see that they are just fine, and see some CEO that makes 100's of millions of dollars as the "other" and not give a shit.
And ultimately, we don't want the laws to be equally applied. Nobody cares if some guy wants to hire his son to sweep the floors at the family business for $2/hour. That's not the problem. We don't want mega corporations coming and and killing the small business entities in that area, thereby essentially monopolizing the labor market, and then paying the whole community shit wages and having an HR department that steps them through the process of subsidizing their income with food stamps and section 8 housing. That's the problem, that's who needs the fucking regulation. Not Ma and Pa's antique shop.
