One common criticism of the topic of self-cultivation is the extent of focus on the "self." The idea of self-cultivation is itself inappropriate because it is essentially self-absorbed and fails to acknowledge the more fundamental communal or social dimension of human life. This is an important criticism, one that Buddhists have faced as directly and as responsibly as anyone in other traditions. The overall Buddhist response to this critique entails two primary points. First, and most important, Buddhists maintain that the beneficiary of your practice of self-cultivation is not just you but others around you, ultimately, the whole of humanity. Early in the career of Mahayana Buddhists who are serious about engagement in self-cultivation, a vow is taken--the bodhisattva vow--in which practitioners vow to seek enlightenment not just for themselves but globally on behalf of everyone. It is the whole of society that needs to be enlightened, not just certain individuals, even if individuals are the catalyst through which such enlightenment might become a reality. In effect, the vow is just to seek enlightenment, at whatever level and to whatever degree that can be accomplished, and not be possessive about it--enlightenment not simply for oneself but on behalf of greater vision for everyone and everything.
The second point follows from the first. We have no choice but to begin this quest wherever we happen to be. If, like most people, we attend primarily to our own well-being, then our interest in enlightenment or self-cultivation or anything else extends only so far as the good we think it will do for us as individuals. If the range of our interest and concern doesn't extend far beyond our own lives, then that is where we must begin, imagining our ethical practices of enlightenment as beneficial for us as individuals, which, of course, they are. Nevertheless, ethical practice, Buddhist or otherwise, functions as a system of training to overcome the narrow and myopic sense of self that we all have in immature stages of development. As human beings engage in ethical self-cultivation--even if they began for essentially selfish reasons--the practices themselves undermine that sense of self, gradually showing us its superficiality and opening us to a more comprehensive vision. The general criticism of self-cultivation as being too individualistic fails to recognize that we are unable to be of service to others until we have undergone enough self-transformation to begin to see larger realities beyond the importance of our own personal well-being.
So we might say, paraphrasing a Buddhist point on this matter, that all of us need self-cultivation up to a certain point of maturity but that beyond this point there is very little point in calling it self-cultivation because our concerns have broadened dramatically to the point where we are just cultivating human enlightenment. This enlightenment is not intended as the property of anyone in particular but as the common good. Making the transition from the primacy of one's own personal development to a broader concern for the well-being and development of all beings is the overarching intention of Buddhist practices of self-cultivation. From that point of view, we are always in the process of shaping ourselves to be more attentive to the needs of everyone, even when, at an advanced point of development, we no longer think of it primarily as a process of self-sculpting. There is no end to the need to open ourselves to the world. There is a beginning, however, and that point of departure is by definition immature, to some extent at least, self-centered. We have no choice but to begin wherever we are and work out from there. The good intentions of self-cultivation are important as motivation for the journey, even if, at some point in the process, the "self" in self-cultivation begins to be displaced by larger collective sources of inspiration.