I for one enjoyed the movie. Even if it’s just Hollywood nonsense, it’s still a well put together film. Definitely one of the better films of the 2010s.
They also got a lot more right about King Paimon than just the sigil: [LONG] An Analysis on Hereditary's King Paimon
King Paimon has also said he doesn’t mind it. After all, any press is good press to a spirit. If that means being made to look like a villain, than so be it.