Whether we are dealing with our own teams or key stakeholders, to be successful in our work we need be to skilled at knowing how to win buy-in, which means getting through to people and causing them to do something different or think about something in a different way.
While our own reasons for wanting people to act or think differently might seem concrete to us, other people have their own reasons instilled in their hearts and minds about why they should or should not do or think as we want them to. People have their own needs, desires and agendas. Sometimes they have secrets they're hiding from us, or they're stressed, busy and often feel like they're in over their heads (but only they know it). They throw up mental barriers in an effort to cope, making your goal of reaching them so much more diificult.
Threats, bully tactics and aggression are poor solutions normally used by people who have not yet developed their interpersonal skills sufficiently to perform their role in a professional and ethical manner. Sometimes these unethical tactics are a last resort when managers or leaders don't know what else they can do. But such action is almost always followed by negative consequences in one way or another.