I disagree. The world is in fact filled with people with this attitude. And it is likely why we're still here at all.

"…it is one of high importance to all those animals which aid and defend one another, it will have been increased through natural selection; for those communities, which included the greatest number of the most sympathetic members, would flourish best, and rear the greatest number of offspring."

—Charles Darwin (the Ascent of Man)

Only if it's not reciprocal. There was another comment here about how someone who helped KK emailed him much later for some help, and he immediately remembered and invited him over to talk. Gratitude leads to reciprocation.

If a species is going to die out anyway, shouldn't it try to go out in a way respectful to its self-identity (assuming it's smart enough to have self-identity)?

Conversely, if the world was filled with people with this attitude, humanity would be living in a stable, post-scarcity situation from a very long time ago.