"I saw something in the sky that I didn't understand" is a perfectly reasonable thing to say, but it's not usually grounds for a major national discussion. "Space aliens are flying through our skies" is an extraordinary claim, and should only be taken seriously in the face of extraordinary evidence.

Instead, all we've got is a rather small collection of blurry photos and videos that hasn't grown at all proportionately to the ready availability of cameras (as one would expect if these were true but rare events), and a handful of personal anecdotes that could be imagined (intentionally or not) or related to physiological experiences like sleep paralysis. At some point, the lack of evidence really ought to make folks question whether it's worth continuing to ask these same questions. When they keep at it anyway, it's hard to take them seriously.