The only good argument is the direct one: it's something we want to do and something we should do for its own reasons and merits. Personally I believe that to be the strongest argument and also a perfectly adequate argument.
But my comment wasn't even meant to highlight NASA's historically documented failures. Instead it was meant to illustrate what kind of project properties are not appropriate for software projects. I was making a statment to the effect that it should be considered a big warning sign if projects are structured like the space shuttle program.
On a final offtopic note about commenting style: you're complaining about deserving more than a witty one-word answer, yet you have no problem with making comments that consist of a passive-aggressive one-word question, do you? Let's keep it friendly, even if we disagree.