Ball lightning is also very rare. So I think the commenter was talking about everyday things that happen with fair regularity, but not to put words in their mouth.
Edit: However, I will say that "explained" in the commenters case does not necessarily mean "explained correctly." Mick West with his Seagull theory for example -- he had the singular video and "explained" the video with an example that fits into our worldview, while the military still has the RADAR, multiple sources of video, and unedited (downconverted) HQ footage and sensor data which would likely monkey wrench his seagull theory very badly.
I guess it depends who you ask. Anyone can choose to ignore solid evidence supporting a hypothesis. Just ask a 'flat-earther' if the Earth is spherical.
{wiki page continues with another 9 theories}
I guess it depends on who you ask. Anyone can choose to ignore solid evidence supporting a hypothesis. Just ask a 'flat-earther' if the earther is a sphere.