Most of these animals wouldn't be extinct if it was not for the negligence of the human race. We killed off many species. Dinosaurs were obliterated from the phase of the earth, so I agree they died for a reason. Cloning is wrong but when you see what caused these animals to go extinct, it doesn't seem that bad to do what is right by bringing extinct species back to life. It's not bringing extinct species that are a problem it's what caused them to go extinct that is.

As for people who are with "we should not play God"
Well, God sure likes to play with us so I guess we can go even with God. There's so many flaws in the Human race, in a race created by GOD. He tempted his own creation. So where's the logic in your beliefs?