So what you need is to free yourself from the bond of aggregation; from Atman and the phenomenal realm, whose aggregation brings creation and its lots of sorrowful qualities (good & bad in every things)).
Buddhists reach for freedom, ... - for a realm that is (and we don't care about what it is) not (at all) of this world.
Let me be a little more specific about this, so I will also answer the question: "Why would you just kill yourself like that by attaining enlightenment and putting an end to your rebirths?"
When I talked about "a realm that is (and we don't care about what it is) not (at all) of this world." I mean by this, that the attribute that is in this world, from the other world (from Atman), is not what we can call a "nice" attribute; for it contributes, through dependant origination, to the stress of this world.
In other words, this "attribute" (that is the "influence" of Atman) , is not the best attribute of Atman we could wish for.
You follow me so far?
So, if you have to get rid of the things of the ego (feelings, smell, touch, perception, determinations etc.), you have also to get rid of not-perception, not-determainations, etc; which are the attribute of Atta (the "influence" of Atman - a.k.a. self).
In Buddhism Anatta (which is very often misinterpreted,) means not-self.
As in perception is not-self.
It means that perception does not belong to self. Perception is not an attribute of self.
So not-perception is self; not-perception is an attribute of self.
And you have to get rid of this also.
You have to get rid of this "not the best attribute" of Atman (a.k.a. Self with capital letter). Which by the way is (Atman) something you don't know about, apart from that "not so cool" attribute that is Atta (a.k.a. self - small s).
It does not mean that the rest is bad.
So to answer the question: "Why would you just kill yourself like that by attaining enlightenment and putting an end to your rebirths?"
Because you would never reach the jhanas that allow you to get rid of such things as not-perception (of all the attributes of the self, of Atta).
So first, you get rid of the attributes of the Ego, then of the attributes of the Atta, and then you wait quietly for death to take the last remainder of perception that you have still in your ego.
You could kill yourself, at that point - or you could teach also.
The End!
Is Atman getting rid of his bad attributes in the all process of creation (dependant origination)?
And does he like us to help him do so?
Certainly!