Well, at least the humans of the village didn't do it for shits and giggles. It's understandable how they felt like this is the only way.
A village of this size has no wealth or influence to give to be able to get top of the line adventurers or the regular armed forces to give a shit about a black dragon following an evil god. Maybe the forces of a the church of the "good guys" might go there if they have true zealots who aren't afraid of nobody, but considering what we've seen from characters in this. I bet you the top guys of this "church" would all probably not send their strong people to die because that would be bad for their general strength and influence.
There really isn't choice for the villagers aside from moving, which in a medieval setting like this is basically asking them to be homeless and penniless vagrants. Much of what they are worth as individuals and a collective is tied to them owning the lands that they own and the tools they are using to produce off this land.
TL ; DR Being poor sucks.