It's frustrating to acknowledge, but everyone gossips. If you choose to abstain then I seriously admire you, but it can be quite socially isolating when you don't get involved with gossiping or b-tching, even passively.
Gossip can be seen in a number of different ways honestly. There's spreading information that you've heard, which isn't wrong per se because word of mouth was our most primitive method of communication spanning back to the Greeks, but it can be damaging or upsetting, especially if the information itself is defamatory. Being consciously mean about another person falls less in the category of gossip and more into b-tching, which is a lot more detrimental to a person's character, and the important distinction to make is that gossip isn't always intentionally hurtful and can just be sharing of trivial secrets - "I've heard Jessica just got a promotion but she still buys off brand tampons, what's that about?" or "Mary slept with Sasha's boyfriend but she doesn't know yet!" - whereas b-tching often digs a lot deeper and confronts much more personal and hurtful issues - "Have you seen how much weight Jessica has gained? She shouldn't be allowed to wear short skirts anymore" or "Mary is so ugly how can she get a guy as hot as Sasha's boyfriend?". Gossip can span from the trivial to the more serious and is usually ephemeral, in that those spreading the gossip usually have a short-lived opinion on a particular issue, whereas b-tching tends to then lead to social exclusion or more outward forms of bullying or intimidation.
In short, both gossiping and b-tching are bad and shouldn't be encouraged, but gossip is the more forgivable of the two. Heck, gossip is picked up by mass media constantly; it's the infringement of privacy which the paparazzi thrive off - there's even a magazine called 'Gossip'! It's so integral to many people's lives, which is utterly twisted but not as insidious as b-tching can be, as it would cause minor annoyance to the subject but the next issue of the magazine their bikini photo is off the front page and another poor sod has been snapped in an unfortunate position. Gossip is bad for the people involved, but you have the opportunity to take it in your stride - see the example of Hiddleston (I think?) wearing the same coat every day so the paps wouldn't look like they were using new material! Hilarious! - whereas b-tching often leads to much more serious and upsetting things, like that poor star in the all-female Ghostbusters who was bullied off twitter as people compared her to an ape. Horrid people, horrid situation. Actively disencourage b-tching and bullying, but tolerate gossip to a certain extent. Everyone does it, and they always will. How you react, however, shows the most about you!