It's possible it reduces the probability of things like wrongly answered stack overflow questions from being used, so it might actually work a bit.

Kinda like how with image generation, you get vastly better results by adding a negative prompt such as "low quality, jpeg artifacts, extra fingers, bad hands" etc, because the dataset from boorus actually do include a bunch of those tags and using them steers the generation to do thing that don't have features that match them.