When you're disagreeable, people will tend give you what you want to get you out of their hair, but in parallel to that, their minds begin forming ideas about how to avoid or minimize future interactions with you.
And that's going to have the effect of you not getting what you want from those people any more; you will have find new people to get what you want.
People also talk: if you're disagreeable to someone, that will not remain a secret that is just between you and then. They will likely be sharing their experience with others, which will warn those others about interacting with you.
So, if we take that into account, being disagreeable no longer seems like a clear-cut optimization of getting what you want as a long-term strategy.
Thus, although the "squeaky wheel gets a greasing", we also have it that "you catch more flies with honey".