I think anything that smacks of wrongness is abuse of authority. People know instinctively when authority is being abused. Bullying and harassment are abuses of authority. Part of abusing authority is abusing your power and not exercising your power justly and fairly. A lot of it probably could be from not having the skills to do so.
Part of being a good manager or a good employer is listening. To develop speak-up cultures, you first need to have managers who know how to listen up. Then people feel heard. If they can go to their manager and their manager doesn't get excited when they perhaps make a suggestion that they've noticed something that could be done better.... Instead of taking it as a personal insult that they haven't done their job as a manager—which is often one of the things that sparks reprisals—they could just learn the skill of active listening. That encourages people to come forward.
That's one of the problems, really. It's just not having skills.