"Why Don't We See UFO's ?"

A question often asked, and the reasons may be very simple. The culture of the world has largely shifted from a lifestyle of being engaged with the outdoors on a regular basis to one where the comforts and entertainments in the home take precedence. In the late 1940' s and 1950's there were more people regularly going to local parks, lakes, and just being outside than is found today. Air conditioning was a rarity, televisions and radios not in every home, and the economics meant the enjoyments of a free outdoors for picnics, get togethers, events, and walks was normative. In those years, there were also a large number of a) local amateur astronomy clubs in America and other regions of the globe, b) less acres of streetlights and illuminated signage washing out the visible sky, and c) people who looked up to see the night sky or the daytime sky. 

Some people - as evidenced by queries and comments when someone posts a video of the satellite strings moving into orbit around the globe - are unaware of what is going on in the skies. Where once people and school children learned the night skies, now there is less motivation or inclination to "look up" or "watch the skies."

It may be a case of "If a UFO appears in the sky and no one sees it was it really there?"  Some argue that with all the sensors and grids and watching electronics anything would be seen if it were there. Did you notice in the last two years several large asteroids "sneaked" up on our planet and nothing (or little) warned us?

The assumption that our radar systems would always be able to track an object of extra-terrestrial origins may be our hubris speaking.