It is easier to understand the popularity if you imagine the support was for Marxism, since plenty of the intelligencia (mostly in humanities?) still publicly support Marxism.
The word "communism" has changed its meaning over time - especially in the USA.
Eric Blair (George Orwell) was not a supporter of communism - he used the word "socialist" for his beliefs and he fought with the "anarchists" in Spain. Both of those political words have changed their meaning too.
Animal Farm was written by him and his wife[1] as a satire of communism because a direct criticism was not palatable at the time. Eric also experienced the Soviet Union undermining a revolution - he wrote about this in Homage to Catalonia https://news.ycombinator.com/item?id=35606380
The most bizarre story is the CIA funding[2] the UK animated version of Animal Farm so that they could change the script for propoganda purposes: "To meet the CIA's objectives, the ending was changed to show that only the pigs had become totally corrupt. The film ends with other animals mounting a successful revolt against their rulers. There is no mention of the humans in the film's conclusion."
[1] https://www.abc.net.au/news/2023-08-12/anna-funder-new-book-...
[2] https://www.theguardian.com/culture/2003/mar/07/artsfeatures...