Scale matters, and the scale that computers/these AIs operate under are absurd compared to a person doing it manually.
The work of a person can be mitigated and a person can be held accountable for their actions.
Much of our society operates on the idea that we don’t need to codify and enforce every single good or bad thing due to these reasons; and having such an underpinning affords us greater personal freedom.
I believe that this kind of generative AI is bad because it approximates human behavior at an inhuman scale and cannot be held accountable in any way. This upends the entire social structure upon which humans have relied to keep each other in-check since the advent of the modern concept of "justice" beginning with the Code of Hammurabi.
In essence: Because you cannot punish, rehabilitate or extract recompense from a machine, it should not be allowed in any way to approximate a member of society.
This logic does not apply to machines that "automate" labor, because those machines do not approximate human communication - they do not pretend to be us.
Should those machines then be subject to your same philosophies? I'd suspect you'd say "that's different" somehow but it is only because you are alive at this moment and these machines have been normalized to you that you do not care about them. Were you to be born in a few centuries, you would likely feel the same way most do about the prior machines, and indeed, you'd be hard pressed to find anyone who think that future generation's AI (probably simply called technology then) is problematic as you do today. Recency bias is one hell of a drug.