in reply to Extraterrestrials haven't visited the Earth yet because:

#2 and #3 really should go together. There probably aren't any suitably capable extraterrestrials close enough to have detected us, decided to contact us and then done so. Note that, unless Einstein was dead wrong about the limitations imposed by the speed of light, extraterrestrials must have the capability to live for millennia in order to either communicate or travel effectively over interstellar distances. That means they would either need to also have the capability to engineer that longevity or they would take billions of years to evolve.