I'm afraid you are severely mistaken. This is only the sixth mass extinction in Earth's history, and the first one that was caused by a species that knew what it was doing. Even on the scale of billions of years, what's going on right now is highly unusual.

Nor would any of the other mass-extinction events have been considered “life proceeds as normal”, if there were any humans around to witness them. Certainly a huge asteroid hitting the planet and shrouding it in dust for years would have turned some heads.