It is always a good idea to hedge your bets. The lifeforms on earth are so very fragile. To ensure the survival of mankind we would very possibly need to reach for the stars within the next hundred years or so. We need to build our knowledge on all aspects of the Universe.

I also think if you start doing some accounting you will find that the budget of space exploration not focussing on satellites is actually not that large. The people of the earth is spending far for money trying to kill each other.

Nice of the aliens to send us back a photo.

The 'photographer' can be seen reflected in the lens of Curiosity's top mounted laser, visible in the upper left of the image. I'll let you draw your own conclusion...

Another possibilty, Opportunity rover is still operating on mars http://en.wikipedia.org/wiki/Mars_rover#Rover_synopsis. Still it would be nice to have a photo credit.