These are not monsters. They are clearly humans.
He seems to be able to do quite a bit, doesn't he? Couldn't he join up in the push and start making calculated comments that prove to be true in order to save the majority of people in the expedition? Wouldn't that be a better method to create a guild strong enough to defeat the demons? I mean, you show insight that is superior to the leaders of the expedition, and surely you will suddenly reap huge rewards, and get a large following underneath him.
Why doesn't he? Simple. That's not his goal. What he wants is personal power. He is only collecting those of use to him in order to increase his own power. He doesn't actually care about the other people around him in the slightest, and only really wants them for how they can benefit him. Example:
Hence why he compares them to loyal dogs and sees them as such. The moment that Kim Han-Byul mentioned that she was thinking of leaving because he wouldn't explain his motivations or thought process, he immediately cut her off. The whole point is: "If you are useful to me and increase my personal power, then I will use you until you are no longer useful."
It seems you want to overlook that he is just in it for himself and does not care about anyone else. That's fine. I understand. He's still a piece of trash MC. That fact won't change.