I think I must understand memes wrongly — what is the 'grey alien' ? if not a meme? Up til Close Encounters, 'aliens' came in all shapes and sizes, since then the grey has been the dominant cultural representation, even being retrofitted into Roswell mythology.

Or is that not a meme at all? Is it just a cultural fashion?

The creator of the meme describes it so well that it's obvious really

I believe the Meme, in what ever form it happens to take exists to share an idea in a quickly digestible way that frequently only works when the idea has a shared experiential root. Its communication that requires a shared experience to be properly relevant/understood.

The clear weak spot being anything conveyed simply, is most likely inaccurate at best. flat out misleading at worst.

For every question, there is a clean, simple direct response. And it is usually wrong.

They often carry fake news.
They usually ridicule others, deservedly or not.
They're usually just click-bait.
They're very often created by foreign trolls.
They fucked with our election.
They may carry spyware or other malware.
They've become a huge part of Internet traffic.
They've started to replace real communication.
There's lots more...