Stewart Brand wrote a controversial piece you should read if you consider yourself an environmentalist, as many of us do. http://aeon.co/magazine/science/why-extinction-is-not-the-problem/
Brand argues that using species extinction counts is not a useful tool. His argument is complex and subtle; I will oversimplify here to goad you to read it in full.
First, extinction is something we want to eliminate. Brand is spending his full time and considerable energies to reversing extinction. He and his wife Ryan Phelan have spearheaded a movement toward "de-extincting" a number of charismatic animals, such as the wooly mammoth. Eventually these techniques could be used widely.
But extinction is overrated as a way to measure ecological health. The science shows extinction rates are actually not as high as media headlines suggest, and sometimes not significant biologically (because they are sub-species). A focus on extinction also emphasizes dread rather than hope, and there is much to be hopeful about in conservation. Brand runs through some of the ways our increased knowledge and technology is repairing what really counts, which is species populations, species abundance, and robust ecosystems.
I am oversimplifying. Read the piece. Stewart writes masterfully and clear. We don't want species to go extinct, to die. But instead of merely avoiding death, we can do a lot more in making ecosystems healthy -- and Stewart suggests a few ways.