Earlier quoted context omitted.
Yeah, but the question nobody's posing is: why should it? That's a question I personally can't answer. I don't see any higher meaning in "leaving a legacy". You'll be dead anyway. Why shouldn't we focus on living a better, more relaxed and less stressful life while we're here to recognize that?
And the reverse question would be: why shouldn't it? Why should I focus on living happily and have family and relationships? I'll be dead anyway, and so will everyone I ever loved. So I guess it's up to one to pick for him/herself. Some want to focus on their own small world, others want to leave behind some lasting change affecting many.
Why do people want to make a lasting change? Purely for intrinsic reasons? Or is there some hidden assumption like for example that it will make them happy in their later years?