Because it’s uncomfortable to see decades of work copied so trivially.
Everyone is standing on the shoulders of those which came before. If LLMs allow us to combine the incredible decades of effort and knowledge and experiences that's gone into building something as great as Postgres, and take that and combine the experience and philosophy that has led to the creation of a language that potentially provides tangible benefits, and for far less human time and effort that it would have otherwise taken...surely something that should be celebrated as absolutely incredible?
LLM companies steal the original work and LLM users dont even know where the replicated code was lifted from or how it was licensed.