The current model for finding near Earth objects is not sensible in anyway. We are looking for objects that might threaten Earth in hopes that we can send up a crew to do something (we have asteroid avoidance strategies but no consensus on what to do) in time after we detect it.
Considering that we did not know about the meteorite that recently exploded over Russia before it was here, we obviously need to develop a better strategy to detect these objects and we need to commit more resources to this effort.
In a more recent example, Asteroid 2013 ET passed by Earth in close proximity. Our discovery came six days prior. It is doubtful that the US, or any country, could possibly formulate an avoidance plan, assemble a crew, launch, and execute in six days if it were a threat to Earth.