Today is the anniversary of the Roswell Incident, which is the subject of various conspiracy theories. I don't like conspiracy theories; that way of thinking always tends to involve being selective about whether particular things are plausible.
There's no reason to suppose that life necessarily exists outside our solar system, or that it is impossible for life to exist elsewhere, but that is not the point: we are invited to believe that intelligent creatures from outside our solar system crash landed in Roswell this day sixty-six years ago.
Is plausible that aliens could master interstellar travel, but not the ability to land without crashing?