When some people rag on gossip they usually mean *malicious* gossip. Which is definitely bad, particularly in small/insular communities where reputation matters a great deal. Even if the gossip is later proven completely false, there is a subtle bias where the negative associations created by the rumors cling to people for a very long time like a pernicious stench. A lot of people will make the subconscious association where if the negative rumors were believable despite being false, then it must be because the person in question is someone who *would* do similar bad things. Meanwhile the original rumor-spreader(s), if they can even be identified, don’t typically suffer any real consequence unless they mess up so badly that it’s very clear that they have a malicious agenda.
And unfortunately, clinical narcissists who tear down others for their own benefit, reckless shit-stirrers, and pathological liars exist. So while gossip is not bad per se (it helps people keep up on what’s going on in their community or social environment) anything one hears really should be taken with a grain of salt. This isn’t quite the “arson, murder, jaywalking” situation it might initially sound like, even if it’s rarely as serious as the other things.