Has anyone ever seen this comet with the naked eye?
Yes, I have. This was from a moderately dark location. You probably won't be able to see it from a city - it's too dim for that.
I think it is necessary to watch in the video to have an idea about its speed and direction.
There are several websites and apps that provide maps showing where it will be at specific dates. You don't need a video to be able to find it. You do need to recognize some constellations and asterisms to have much hope of finding it, however, although this one is bright enough to be easily spotted from a dark location.
More importantly, when was this comet discovered?
The object was discovered by a team using the WISE space telescope under the NEOWISE program on March 27, 2020.[1] It was classified as a comet on March 31 and named after NEOWISE on April 1.[3] It has the systematic designation C/2020 F3, indicating a non-periodic comet which was the third discovered in the second half of March 2020.
Its designation gives a general idea of when it was first cataloged, which is typically soon after it is discovered and verified by independent observation. Why is this particularly important?
If it was, why didn't NASA explain it years ago? Why are such things explained after observing all the time?
Because nobody knew it existed before it was first noticed in the WISE data. Only after something is discovered can it be studied and characterized. This comet was quite dim when it was first recognized. Because it has brightened enough to see in small telescopes and binoculars, not to mention naked eye, it has been observed more than most comets.
Why does this seem baffling to you?
Or do your "satellites magically standing in space" observe space?
What?
Who and why has named it Neowise?
As already discussed, Comet NEOWISE gets its name from NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), a space-based infrared telescope dedicated to looking out for potentially hazardous asteroids and comets.
From the late 20th century onwards, many comets have been discovered by large teams of astronomers, so may be named for the collaboration or instrument they used. For example, 160P/LINEAR was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) team. Comet IRAS–Araki–Alcock was discovered independently by a team using the Infrared Astronomy Satellite (IRAS) and the amateur astronomers Genichi Araki and George Alcock.
Thanks in advance.
You can look this stuff up yourself, you know.