Absolutely fantastic achievement, been following this VERY closely and the amount of things that had to work at EXACTLY the right time to complete this mission successfully is astounding.
The negative Neddys are not seeing the wood for the trees.
Sure there are a million reason NOT to do anything in life, if we as a race sat and counted beans rather than push the boundaries of our curiosity then we would have been extinct many many years ago.
What bean counters fail to see is how a man'd mission to Mars would inspire a new generation, inspiration which is dramatically missing in the the generations younger than 40.
We as a species are doomed, everything we have ever done will eventually be obliterated into absolute nothingness.
It won't matter if you were Albert Einstein or Alexander the Great, any feats you will have accomplished will be eradicated when our species, planet and solar system dies.
The ONLY way we as a species can assure long term survival is if we explore, is if we build things not because they make financial and logical sense, but because we can.
The current best theory is that as our universe is expanding it will eventually get to a point where it's expansion will have exceeded all the mass in the universe, when this happens our best guess is that the "Big RIP" will occur.
This will tear everything apart in our universe down to nothingness.
So if we are not out and in another universe by this time, it will simply be as though we as a species never even existed.
Sure we could build a space craft that could travel just below the speed of light.
Problem there is, the edge of our universe is expanding faster than the speed of light, so if we set out tomorrow at the speed of light we'd actually be further away from the edge of the universe the day after.
So our only longggggggggg term hope is to push the boundaries in the hope that we stumble across something we could have only dreamed of like worm hole.
If we don't then as a species it really doesn't matter how much money we made or what we did it will be all torn into a vast nothingness.