We care about this dumb asteroid because it can tell us a lot about the evolution of our solar system and the origin of meteorites. Specifically, it can help us determine an accurate shape map which will tell us Eros' density. It will also show us if there are small-scale heterogenieties on Eros' surface, and a crater count can tell us Eros' relative age. All of this will help us learn what Eros is made of and tell us about the beginning of our solar system.
Finally, it took a whole summer to do because there are a huge number of things we had to take into consideration -- it's just a really difficult problem.