What sins did the Dinosaurs commit for God to wipe them out with an asteroid and mass starvation?
If that's true (it's bullshit) then the god fairy thought it had better do something to make it possible for small mammals to develop into primates and eventually human apes.
The truth is that asteroid hit Earth by chance instead of smashing into our solar system's vacuum cleaner, Jupiter. If not for that asteroid those small mammals would still be hiding underground or on the top of trees to hide from the dinosaurs.
Reality is a wonderful and interesting thing. The religious imagination is boring and ridiculous.