But there are problems and concerns. Cost, viability, environmental impact should the species be returned to their habitat--if their habitat still exists. What implications might there be? Would they be susceptible to diseases currently in the environment? Would the revived species be little more than isolated oddities maintained at zoos and restricted sanctuaries?
Here's an article that debates the pros and cons of de-extinction efforts:
Link: Should We Start De-Extincting Species that have Died Out?
I think it's a worthwhile effort. What can be learned by building the science and technology that would go into successfully completing such a project? What spin-off technologies might there be? Who knows? Who could've predicted all the technological benefits derived from the space program began in the 1960s?