Without focusing too much on it being the biggest copyright-laundry scheme ever, and also not speaking as a teacher & how AI harms the learning process by removing obstacles that are vital for deep/healthy learning, the main argument is mostly related to control and technological dependence.
A technology can make you more efficient while simultaneously making you less capable of functioning without it.
With AI coding, the concern is that if you outsource the planning, debugging, architecture, and implementation often enough, you may gradually stop developing those abilities yourself. Eventually the tool goes from "assistant" to "something I cannot work without."
The burning question here is... is the technology increasing your capabilities, or replacing them?
Most people were already slop coders and did not care about the underlying understanding of their code before 2025 anyway, but we still need kids that know every inner detail of how technology works to make contributions to real breakthroughs and proper creative innovation in the future.