Nations have a long history of funding exploratory ventures. It is generally understood that the process is useful for a variety of reasons: it creates jobs, there is a small chance that something practical could be discovered, and most importantly it satisfies a basic human need to know more. With this mission in particular, we may be able to answer some very fundamental questions about the arrival of organic compounds (or even life) on Earth...surely that's worth spending some money on?

You have the right to feel however you want, but a world without curiosity would be pretty sad; the internet wouldn't even exist for us to have this discussion.