Woolly mammoths look cool. In all honesty, I think that's the main reason. De-extinguishing species is interesting as a scientific exercise and will probably l

Woolly mammoths look cool. In all honesty, I think that's the main reason. De-extinguishing species is interesting as a scientific exercise and will probably lead to advances in fields of genetic engineering, medicine, the history of life, etc... We don't have to do it with woolly mammoth, we probably could do it with some other unremarkable specie. But doing it with woolly mammoths will certainly attract a lot more attention and therefore money for the researchers. There is also an advantage of doing it with a large animal we have already killed off. That is that if we lose control of our (re)creation, we can easily kill it off again, assuming it doesn't happen naturally. It is better than to de-extinguish a specie that is small and particularly well suited to human environments, we have already made enough of a mess with existing invasive species that we don't want to bring new ones.