Re: Why go to mars?
I'm of two opinions on this:
Why not go to Mars? Prove that it can be done. Send people there, take good surveys, look into places that robots will have a hard time doing themselves (drilling into the crust, on-site testings, etc.). If we could send people there it would create a huge funding opportunity for many, many people. Research into space travel, living accommodations, anything related to it would surge.
Then again...
Why even ask why to go? Don't. There are enough problems here on Earth that need to be taken care of before we invest huge sums of money into a task of that magnitude. People all over the world are without health care, food, proper shelter, clean water. Earth's resources need better management, over-population needs to come under control, war is always occurring. If we can't solve (relatively) simple problems like this on our own home turf...why should we send people out into space? If anything it would cause more conflict and create more enemies than there currently are. Property rights of new lands, criminal outposts, you name it, it could happen.
I suggest we solve one problem at a time. First, let's find some clean, renewable, efficient energy. Then let's feed the hungry. Then let's go to space. It'd be nice to punch a zergling in the face.