Oh? Presumably they couldn't, based on whatever restrictions this island enforced on them.

Namely, time. Resources. Keeping the garrote off of their own neck or someone else's. I've been threatened with no such thing, but I suppose I'd need someone whose fate I cared about so much for that.

They may also be playing to position themselves at an advantage for a future move. It's not fun if you throw the whole chessboard in the fire.

At the very least, I should conclude we aren't looking at desperation.