Most workplaces tend to have disputes and it’s likely that ‘talk’ around the workplace may sometimes be of a negative type. Rather than engaging in the negativity, you should avoid sharing these kinds of opinions with others as this can reflect badly on you.
This doesn’t mean that you can’t supply any kind of constructive criticism to your fellow co-workers, but it’s always best to steer clear of behind-the-back antics that may hurt and offend not only the person they’re directed at, but also your future career.