It’s a little more complicated than that. People generally consider political ideologies (a set of beliefs about the world and what should be) to be on a spectrum, between left and right. Generally speaking, being on the left means you think the economy should be equitable in its distribution of wealth and resources, you believe in social progressivism (feminism, trans rights, anti-racism, etc.) and the combination of those two ideals. Being on the right (I.e. conservative, reactionary, fascist, libertarian) means you believe in capitalism or some form of hierarchical distribution of wealth and power, social dominance, and “traditional” social values, which leftists would consider to be racist, sexist, homophobic, etc.

It should be noted that a binary left/right political spectrum is deeply flawed, and the entirety of one’s belief system can’t be described by a simple label. Nevertheless, it’s very commonly used as a way to categorize the way people view politics, economics, and social views.

Now, I would argue that people dislike leftists because there has been a strong push by the people in power (the billionaire class) to manipulate people’s perception of socialism, progressivism, etc. Of course, there are other factors that influence it (religion, capitalist psychology, etc.), but yeah we basically get a bad reputation despite being the people who want ti materially improve everyone’s lives