Re: well , there you have it....
Astronauts, if obsolete, are only obsolete in the context of robotic exploration and some very basic science. (But Buzz Aldrin noted that all of the research findings of all of the Mars rovers and landers over the last 30 years could have been accomplished in a week or two by human astronauts landing on the surface.) There are many, many science experiments that could be done on the surface of other bodies by humans that are essentially impossible to do robotically.
There is also the element of accidental discovery. If the ISS were not 'humanized', many of the things we have learned about space and physics in microgravity would not have been observed or discovered. A rather mundane but amusing example is how liquids behave in microgravity - see Col. Hadfield's video of how water wraps around objects including his hand.
But more important, for those of us who are convinced that humans, and Earth life in general, must be propagated across the Solar System and beyond, astronauts are the whole point. Scientific research stations are a first step. Every bit of scientific and technical advance brings human space habitation that much closer.
There are also good, economic reasons, if/when space industry develops, it will gradually become cheaper to have humans living in space to fix and run things than to do it all completely robotically in space. This is nontrivial. A recent article (2012?) by a prominent economist showed that space industrial development had the potential of improving the standard of living of everyone on Earth by a factor of 10. In my view, there are four non-science aspects: our existing and expanding Earth Observation systems, tracking weather and other things are now saving thousands if not millions of lives every year, and improving our drive to work; things like Space Solar Power have the potential of eliminating all of our coal, nuclear, oil, and gas-fired electrical power plants; a wide range of new technologies that will only be manufacturable or operable in high vacuum and/or microgravity will drive yet another technological leap forward; and finally space "mining" - extraction and retrieval of materials that are hard to find on Earth, such as platinum (platinum would be a widely used industrial metal if the price weren't so high - extracting from asteroids has the potential of cutting the cost by a factor of more than 100.)