He considered her words and nodded his head in agreement. So he continued felling trees and didn't sign up for the rescue mission.
The rescue mission should be easy because Command knew the location of the kidnapped soldiers; they had geographic knowledge and even visual images of their surroundings through their marks, and they also knew how many and how powerful the guards around the soldiers were.
So it should be very easy for a rescue mission to be planned and executed as they had all the necessary information for a successful rescue. But Kelvin still didn't join them because of the uncertainty known as demigods.
Sure, there will be a lot of rewards for the abducted soldiers and those sent to rescue them, but no one would be able to earn those rewards if a demigod shows up and wipes them out.
It is like Wrath said; the large amount of merit points being offered isn't for free. They are directly proportional to the danger involved in the missions.