I'm not really able to explain to students why I think that using generative AI (e.g. chatGPT) for writing is bad. At least, not in a way that convinces anyone.

My argument is basically this: writing is thinking.
In order to write about research clearly, you need clear thinking. The act of writing a paper/report helps you think about it more clearly, because all those fuzzy gaps that your mind can just jump over show up very clearly on paper. So, writing is a way to figure out your own thoughts and not only a way to tell others about them.
I think that’s an essential part of doing science and something that you cannot and should not outsource to a machine.

I don't know how to express this in a way that makes sense to my students. Sigh.