>He ignores the fact that some of us aren't happy unless we are doing something that stands to make a double-digit percentage of humans on Earth happier, cleaner, safer, healthier, or more efficient.
That's precisely what I'm arguing is not a healthy attitude. If you're unhappy now, I don't think you will be satisfied with what you have done and would be able to die peacefully _once_ you get featured on Time magazine proclaiming how you reduced poverty in Bangladesh. By then, your goals would have moved to something even bigger. By all means, improving state of humanity is a noble goal but being unhappy because you haven't been able to make sufficient progress towards it is an unhealthy attitude.