The species over the individual "narrative" exists because it is a fact of evolution. Life is a pattern of self-replication, and it is at the level of the gene that natural selection works to make this pattern more robust. The whole concept of having an individual "over" a species is so quaintly human. The universe, and the physical processes within it that are life, have no concern for such silly concepts. To put so much stock into the individual (and such people are always really talking about themselves), is completely egocentric. We tell ourselves stories about how important and special we are to validate our own existences, and that's fine, it makes some of us feel better. But we ignore the macro-processes that even allowed our existences at our own peril. Guess what, with no species, there are no individuals to glorify.
>do you also consider it ethically acceptable to kill an individual once he has stopped procreating, since he's no longer relevant to the evolutionary game?
The evolutionary game is much more complicated than you imagine it to be. Humans have evolved to be social animals. Someone who is too old to procreate can still watch after young, pass knowledge on to them, etc., which increases their fitness. This is such a fundamental misunderstanding, you have no reason to be so confident in such matters.