Beneficent behaviours as you have defined, are a narrow sub-set of so-called beneficent behaviours and makes an assumption that only "altruistic" behaviours (characterised by giving, selflessness etc...) are beneficent.
Philosopher Ayn Rand noted that there was "no conflict of interests among rational men", the full quote states:
The Objectivist ethics holds that human good does not require human
sacrifices and cannot be achieved by the sacrifice of anyone to
anyone. It holds that the rational interests of men do not clash—that
there is no conflict of interests among men who do not desire the
unearned, who do not make sacrifices nor accept them, who deal with
one another as traders, giving value for value.
This suggests that a man can act in a self interested manner and still achieve so called beneficent results.
I challenge your premise that we have to be obliged to act selflessly. I instead suggest that through reasoned, selfish, action we can achieve a state of social harmony and remove the poverty and suffering charity is supposed to alleviate (There is nothing wrong with charity, per se. I am just saying there is no moral imperative to act in a charitable fashion).
As to the essay you linked to I found it a little disturbing. The author (of whom I am unfamiliar) seemed more concerned with "society" and the poor and destitute than with individuals. I recognise this trend in modern philosophy - that is, the trend to disregard the individual as inconsequential or irrelevant - but I strongly recommend you look elsewhere for arguments for or against altruistic behaviour.