Well, it's just the nature of zero cost (or more properly, fully externalized cost) for false positives. Recruiters in the wild have literally no reason not to be spammy, because it costs them absolutely nothing to be (and because everyone else is being spammy, so everyone assumes they're being spammy). It's a crappy tragedy-of-the-commons equilibrium for everyone involved - they don't much like it either, but don't feel like they have a choice.