We’re probably getting a bit off topic with all this Wicker Man talk, but…
I haven’t seen it in a while either, but isn’t it implied or explicitly stated that the whole missing girl thing was a ruse to get him to the island and be a sacrifice?
Either way, I think Lord SummerIsle and the rest of the village are meant to be “bad guys” in the story. You don’t feel their winning is a successful resolution.