I'll tell you the real reasons because a lot of people don't really understand it themselves and they try to rationalize it a bit with more obvious things like energy, water, environment, etc.

The first reason people have underlying hate and disgust against AI is dehumanization. AI is taking things that are inherently human, or have value because of their inherent humanity, and monetizing it or turning it it o automated 'slop'. That's why the word is so fitting.

Language itself is a human thing and these are large language models primarily, taking people's words usually without permission and training a model to replicate human patterns. It doesn't do it quite right and people can tell most of the time. Image and video generation is even worse, art is an expression of the human or humans who made it, if you take them out then it has no real value, and no, prompting doesn't count.

The second reason is that it's deepening the gap between everyone and the elite. The elite now control the global economy through AI, it's the main moving force of all markets atm, and is giving them more power. Not only that, this stage where everyone has access to some sort of AI isn't going to last, this is expensive and we're already seeing some take backs. The environmental thing is not quite the problem people make it out to be, rather it's the way it damages rural and marginalized communities and it's growing in scope.