I've heard that it was the foundation of some of the worst dictatorships in history. Is self sacrifice a bad or good thing in the long run? Is it better to be selfish? Is selfish desires better for society?
There has always been a tension between social hierarchy and a sense of oneness with life (or if we are particularly miserly, just our life ... namely "humans" .... or if we are even more miserly, just our race, creed or family).
Without social hierarchy or social contracts there is no way for people to meet their own needs (just imagine if you had to make your own clothes and grow your own food by yourself) and without some sort of collective empathy we would have been subject to a very reptillian introduction to this world (reptiles aren't famous in the animal kingdom for their doting parenthood skills).
So historically you see this boom/bust cycle around value revival movements. Like some group will be advocating some cause, and people will reciprocate with their sincerity with wealth and political favours .... and after some time, the practitioners take it for granted and get too caught up in the social hierarchy and the whole thing falls into hypocrisy ("power corrupts and absolute power corrupts absolutely").
Just as an example, we see this with jesus washing the feet of beggars and forgiving the sins of the adulteress, yet a couple hundred years later christians are brutally killing each other in the name of the prince of peace. Or in the case of hinduism with an underlying philosophy of the oneness of all life yet the lower castes suffering so many injustices .... however the undisputed champion in this field of hypocrisy belongs to communism, where they secularized this "oneness of humanity" towards brutal ends (consider what Pol Pot achieved in a decade).
So its not so much that altruism requires a healthy dose of selfishness to function, but rather it is required that there is a healthy balance between social hierarchy and a place within that hierarchy for leading examples of people who establish that sense of oneness with life.
As far as social hierarchy goes, the upper end tends to work better when there is a clear distinction between the executive, judicial and legislative arms of government. When too many people are wearing too many hats, it tends to pave the way for degradation. Historically persons may apear who had the capacity to wear all such hats simultaneously however it is unrealistic to expect a successive continued lineage of such empowered personalities. Historically it is also not uncommon to see people who function at the top end of society in the role of advisors adopting austere lifestyles somewhat aloof from the acquisition of power etc ( I am thinking of the priestly estate or the brahmanas ... of course history illustrates that they, for the most part, adopted "many hats" and fell on their own swords).
As far as a sense of unity or oneness or quality of life goes, secularism is crippled at the onset in defining the notion of everyone being equal, much less establishing a plan of action to navigate the boom/bust cycle.
The subject of transcendence (the subject that establishes how we are all equal .... many may disagree of course but in the meantime, apply whatever material tests you want and everyone will continue to provide different material results that fly in the face of the notion of us all being equal).
The subject of transcendence of course belongs squarely in the realm of religious/spiritual disciplines .... but many are struggling with historical issues of hypocrisy or have been poorly represented ... both of which tend to land them in the same boat: an inability to be philosophically coherent and/or socially relevant.
So, in short, unless and until we see a re-emergence of spiritual leadership (ie a successful crossover between social hierarchy and capable proponents of the oneness of life), altruism (or indeed, any sort of "ism") will simply meet the boom/bust cycle according to the criteria of the economic needs of an industrial civilization (fasten your seatbelt).