I admit my complete ignorance in this matter. I do not understand why this would induce them to remove their links. They do not seem to have anything to gain,

I admit my complete ignorance in this matter. I do not understand why this would induce them to remove their links. They do not seem to have anything to gain, and actually, it sounds like it might be highly gameable as a form of negative SEO. At best, it seems to me that there would be an inverse ratio between the likelihood of the link being removed and the spamminess of the linking site. If someone could explain this, I would be grateful. [alternately, I'll delete to reduce clutter if I get bumped down some more.]