Did you know the first "area 51" type facility was White Sands Missile Range, just miles from this allegded alien crash site?

Did you know they took captured Nazi aircraft to this location to back engineer?

The US military was testing the Nazi's flying wing, it crashed on Mack's land. Since we just got out of war with the Nazis, the government did not want anyone to know they were capturing Nazi tech, spies and scientists (Paper Clip) so the cover story was alien's crashed. This is far more plossible than a crashed alien ship. Its the simplest explanation.

Radio, then TV, is why people believe in aliens. Not because anyone has seen a real alien. Nobody has tangible proof of that.