There has been much written on subject of stoicism, and much misses the main point. It is not suppression of emotion. It is about understanding the source of the mainly negative emotions, and the causes. The positive emotions are good. Once we understand the cause of negative emotion, it is our choice to get anger or use the negative emotion or see the cause, eliminate the cause, and move on. Some things are up to us, our opinions, our beliefs, our values, our judgements. Live by nature, and to do that we must understand our nature. The product is understanding of our behaviors and thence to have a choice.
It is a form of consequentialism.
There is no reason to get mad at inanimate objects, it is not there fault. They have no intent, no purpose other that which we paint on them. They are a collection of atoms, nothing more. Perhaps the do what we expect by habituation, perhaps not. It is not there fault, they have no intent. It is all in our mind, our intentions, our expectations, our delusions of how life should be, our attachment to a mortal or a thing, or the opposite, our aversions. It is all in our heads. It has nothing to do with the object, it is all us and our mind. In Buddhism, this is the second noble truth.
Now people are just like inanimate objects, but they do form intent, but usually we do not enter into the consideration. We are just moving objects without significance to most others. That is the way we treat many people in the cities where we know few of the surrounding people.
Nature has no intent. It just provides an environment for this opportunistic species, of which we are part, to flourish. There is no plan. Man has created an intent or purpose to develop, a outlet for our natural desires. Directing our desires is man made. Controlling ourselves is good; controlling others leads to resentment, rebellion, resistance, over through, and similar distress.
We need a common goal, often taken to be development of a cosmos, or a flourishing society. Anything that leads to, aids in, supports, sustains, such development is taken as purpose, and is in the right direction.
But what do I know.