Classic gossip, … telling it entails several … basic motives. … It enables the gossiper “to do dirt to the person he is gossiping about.” It entails “sheer jolly prurience.” It presents the gossiper as “up to the moment, in the know.” By no means least, it reminds us that “part of the delight of gossip, after all, is, to use an old-fashioned word, its naughtiness.”…
Why can't everyone enjoy gossiping about humanity in general instead right?
Talking about each other is illicit only if you are not prepared to tell me in the face what you just said about me behind my back. And if you are not, it's because you'd rather not jeopardize the default or intentionally created goodwill towards you. Seen this way, discussing others is the natural behavior, while excluding some (primarily the subject) from the discussion constitutes a deviation in the interest of manipulation, which is understandable, if morally questionable.
Thus, if there's anything to ban here, it's decisions based on irrelevant grounds. But evidence suggests that such bans, where they do exist (in court, for example), are ineffective. Hence the status quo.
The "gossip" sermon from the movie "Doubt".
Do "we"—as you claim, our species—consider gossip "naughty"? I'd be surprised to learn hunters and gatherers regarded it as improper, but I don't really know.
Seems to me this could put your viewpoint to test, something you seem ever so reluctant to do; if hunters and gathers engage in gossip without compunction, you're probably wrong (in the sense, at least, of requiring a readjustment of your priors :)) But you could take some comfort from the fact—were it a fact—of universal ambivalence toward gossip.
This isn't a terribly complex puzzle. The content of gossip is almost invariably negative. People don't feel guilty for talking about the fact that Jane's daughter got into Harvard. If, however, they further claim that she got in because Jane made a lavish donation, or seduced an admissions officer, or some other negative thing, then the "naughty" feeling attaches. If this fact is, somehow, a matter of public record, it ceases to be gossip.
Gossip is "naughty" because it is, in some sense, harmful to people within our social circle. Them knowing about the existence of such gossip is even more harmful in most cases. Sharing gossip is therefore an exercise that expresses a great deal of trust in one's confidants - you express trust that the people you are gossiping to will not tell the people you are gossiping about. We don't think it improper to talk about each other, we think it improper to tell potentially harmful information that is not already entirely public to other people. On the other hand, this behaviour, because of the trust it presumes, also builds social cohesion.
As to the making it illegal would be "too far," even ignoring, e.g. the First Amendment, there's just no way to police it in any practical sense. Can you imagine if any alleged gossip gave rise to a cause of action? Back in ancient times, the law was basically a tool the rich could use against significant political opposition. I doubt you'll find many cases of Housewife v. Housewife from the Ancient Rome - unless at least one of them was powerful and meaningful harm resulted.