We live in a universe where all things decay. There is no known exception. Species go extinct. Stars die. As best we know, the universe itself will die: http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe
You and I will die as well, and pretending otherwise causes a lot of harm. The best we know how to do now is to extend life a little; but we don't even do that as well as we could because we waste fantastic sums on futile end-of-life care. And that money also doesn't make it to the medical research that could help the next generation, or the one after that.
But I think the harm is deeper than that. Who do you think is more likely to be fully aware of how short life is? The next Einstein now toiling in a lab? Or somebody watching their third hour in a row of reality TV?
Don't throw out the Einsteins because of people like this. People who throw their lives away will end up killing themselves anyway (e.g. through horrible eating habits, smoking, etc.), and even if they don't, they'll be in their living room out of our way.
I find it highly amusing (if sad) that people who argue pro-death always like to point at people they don't think deserve to live...
In the coming decades, We may or may not be able to significantly extend life, but it's not clear why it's unlikely, or why it causes harm to even think about.