I hadn't heard of the Wicker Man, so I looked it up. Wikipedia says it made less than $80,000 at the box office. Does that really qualify as "popular"?
The Wicker Man is well-regarded by critics. Film magazine Cinefantastique described it as "The Citizen Kane of horror movies", and in 2004, Total Film magazine named The Wicker Man the sixth-greatest British film of all time. It also won the 1978 Saturn Award for Best Horror Film.