Because even if you had the wingspeed of a hummingbird, it would provide no evolutionary advantage other than being able to swat the lion a few more times before it ate you!
Take it further, WildTurkey. If I had the wingspeed of a hummingbird, what would prevent me from having the strength of the lion, and the eyesight of the eagle, all at the same time.
Does the theory of evolution prevent me from having these in combination? No.