Upon meeting someone, you create a certain impression. That impression is technically who you are according to that person. He'll most likely not be able to see you as you are but only interact with you through how they perceive you. Adding to this the fact that you hold the power to set social boundaries.
As discussed in Outgaze, "When building a house, the pillars are never too close" Social boundaries are needed for fruitful and useful social interactions. The lack of those is what can create impulsive actions or whatever behavior that can be named horrible.
You create how people react to you because if you just care enough to maintain a good impression based on who you truly are rather than putting a facade of superficial charm and you maintain social boundaries that stand for what you stand for, People would hardly respond poorly to you.
Think of it as such, if a person gets a positive stimulus from you, they would most likely react in a good way. If they get a negative stimulus however, they would most likely react poorly. That in mind, one might assume that some people tend to behave poorly for not how you treat them but rather because they have a tendency of treating people poorly or for whatever reason. In that case, the safest bet is to put those boundaries in work for the mere reason that we, as humans, rarely cross boundaries unless we know the person isn't going to retaliate.In general, we're more at an anxious state because we're trying to determine how to act with people than we're comfortable. The more boundaries you keep the more anxious would be around you, giving thus, in the process, more thought to what they'll do or say.