Actually, from a purely rational point of view "woman and children first" has merit. First, as stated above, women are important for continuation of the species. Children however, do not have the capability to defend themselves as does a grown man. In a burning building or on a sinking ship, a man has a much better chance at swimming, leaping out a window, or breaking down a wall.
Also, while an adult male /may/ have some viciously practical value to society at this moment in comparison to "only a child" the child's very potential to grow is what's valuable. A single child has potential to grow into an improved human being, having learned from the previous generation's discoveries and mistakes. A grown man has already made many, if not all in some cases, of his critical contributions to the world. This is in fact why many adults willingly put the child first in a life and death situation. It's not just sentimentality for the innocence of a child; it's practical realization that the child has a lot more yet to do in life.
It is of course, all situational. When the airplane is going down, you'll want to hurry the man who knows how to fly a craft to the cockpit over taking a moment to strap in a kid.
As for the OP topic, an interesting comment upthread about animals inherently preferring their own kind, thus too much interest in human animals must be some kind of mental disorder, actually opens up a few more questions.
First, other animals can, and do, empathize with an accept other forms of life as "one of their own". Some animals will raise a member of a different species as their offspring. Others will pack-bond with outsiders; with the obvious example being that canines will bond with humans as alpha leaders. (They've been bred for subservience, but the point is that it happens.) Other animals from cetaceans to great apes can and will recognize others, such as humans, and respond to them in a manner equal to their own kind.
Second, humans may be animals, but there's a particular fallacy sometimes called the Naturalistic Fallacy. This basically says it can be misleading to apply "natural" standards to human behavior not because humans are not animals; but rather humans are animals capable of subverting nature. The human animal has gained sufficient sentience to adapt to the world around it in ways most other animals cannot. This changes how humans relate to other species, as well.
For example, one could say that the reason why a dog may take on a kitten and raise it is because of "confused instincts". It's small, fuzzy, and is too similar to a puppy. Perhaps; with humans though, the ability for the human brain to conceptualize relationships between animals is much greater than that of a dog. Humans can think more abstractly. So they can identify common traits between themselves and a wider range of other animals, even ones that aren't primates or haven't been specifically bred for human companionship, such as the dog, the house cat, or the domesticated horse.
All this, by the by, does open the door for special kinds of human malfuctions - since the human mind is far more flexible in forming connections with other animals, if something gets screwy, the results can be spectacular. (The PETA supporter who literally despises humans and thinks cows are far more important, the cat woman who collects 60 cats because she's obsessed with them, etc.)
I think the problem though is that some people are confused by the empathy others have for animals when they've never been in a position to develop that empathy themselves. To them, /any/ degree of concern or mutual identification seems utterly nonsensical and "insane". Ironically, it's also a facet of human nature that can cause people to not understand what they see, and judge (then dismiss it) in thin slices and first impressions.