This is invisible on paper but readable if uploaded to chatGPT.

This sounds fake. It seems like only the most careless students wouldn't notice this "hidden" prompt or the quote from the dog.

Maybe if homework can be done by statistics, then it's not worth doing.

Maybe if a "teacher" has to trick their students in order to enforce pointless manual labor, then it's not worth doing.

Schools are not about education but about privilege, filtering, indoctrination, control, etc.

Shouldn't be the question why students used chatgpt in the first place?

chatgpt is just a tool it isn't cheating.

So maybe the author should ask himself what can be done to improve his course that students are most likely to use other tools.