I'd already seen this article elsewhere on other photographic sites. In this article by the BBC, the text refers to 'dual standards' contrasting the reception this image had with an almost identical one that featured a mother and child. This is less about dual standards and more clearly about unconscious gender bias; it reveals to us the way we encode paternal relationships as being pejoratively different to maternal ones.
As for merit of photograph, it is at once both sensitive and revealing. It shows the vulnerability of both parties in the shot; the child who is seriously ill and the father, who is aferall naked and revealled to the world.