Philosophy, et cetera is discussing selfishness
His definition of selfishness is a fairly normal one
selfishness = "an inappropriate disregard for others"
this resuts upon the definition of "appropriate" as long as you define that as "appropriate by my moral standards" then genes have nothing to say about it because your moral standards (or mine) are not physical things in the world that genes could take cues from.
But I wonder what one would do with these definitions that makes them so useful. a key problem is the "first you save yourself then you save the world" (quoting form a song) issue continuing "it doesnt help us very much if you throw the line to someone else".
Excessive amounts of altruism may be bad - in fact a strong capitalist might argue that all but the smallest amounts of altruism (in specific situations) are bad. And the above examples of extreem altruism are obviously ridiculous (in fact worse than evil selfishness) because everyone would drown while throwing the line to each-other (and generally driving each other insane).
So arbitrarily defining altruism as good seems flawed.
The question then is - is utalitarianism altruism? what about socialism? is that a better form of altruism? what if you are a poor socialist?
It seems he is very eager NOT to use biology as a solution in psychology. Personally I see this as a great weakness in psychological research probably a result of people trying to protect their turf. It is lucky chemists do not seem to see physists in the same way.
When one learns about plants one talks about photosynthesis and nowadays one learns the chemical reactions and when one learns about the chemical reactiosn one learns about the electrons and basic physics of it, with things like entropy in mind (using potential energy and turning it into heat). One does not have to talk about entropy when discussing the growth of plants but the chain of logic is possible to follow most of the way - even in a childrens text book.
Anyway sumarising the other argument which skips the moral side..
genes are "selfish"
in general genes "effectively" identify their survival with the human host
genes control the human host
thus genes make the human host selfish.
But obviously that does not stop other effects - In addition there are a number of others - these are
the meme effect as noted by Doug (basically peopel with altruistic ideas are popular so altruism becomes popular)
the general benefits of sharing (evolutionary psychology)
the desire hang over effect as I noted (basically one continues to want to help people if helping them when you were young gave rewards - as long as the cost never reaches a certain point)
spandrel effects as ConciousRobots noted (these are side effects of useful genes)
and just random mutations.
All of which are then moderated by genes but are also "default facts of the universe" (ie a gene would generally have to go to a specific "effort" to resolve the issue).
There is quite a lot of added value and understanding in thee I am surprised anyone would want to deny it.