The reason is that it is nothing but a lie.
There is a facade of fake kindness and smiles, while under the skin boils someone who is waiting to hurt you.
I mean, passive aggression feels like the guerilla warfare of interpersonal conflict.
But take the other side and ask the opposite:
What is the alternative for an enemy at the office?
You can’t fight them at work or ignore all contact, can you?
One has to be a professional and play nice – even if that’s not how you feel on the inside.
I would just tread lightly.
This tendency of ours to judge things in simple terms explains why passive aggression is so devilishly effective as a strategy and why so many people use it—consciously and unconsciously. By definition, people who are acting passive-aggressively are being passive and aggressive simultaneously. They are outwardly compliant, friendly, obedient, even loving. At the same time, they inwardly plot and take hostile action. Their aggression is often quite subtle—little acts of sabotage, remarks designed to get under your skin. It can also be blatantly harmful. When we are the victims of this behavior, we find it hard to imagine that both things are happening at the same time. We can manage the idea that someone can be nice one day and nasty the next; that is just called being moody. But to be nasty and nice simultaneously—that confuses us. We tend to take these people’s passive exterior for reality, becoming emotionally engaged with their pleasant, nonthreatening appearance. If we notice that something is not quite right, that while seeming friendly they might be doing something hostile, we are genuinely bewildered. Our confusion gives the passive-aggressive warrior great manipulative power over us.
-Robert Greene, The 33 Strategies Of War