@Mitsuboshi
That's where you are wrong: if you go read the first chapter, you will see that "adventurer" is a job issued by the government, and that killing monsters is a job requirement. From what we can see, they are part of the self defense force, and they are required to fight in stampede.
It's a bit like saying you want to be a policeman because you like to carry a gun, but then you don't want to patrol the streets or fight robberies because it's a chore and people should be strong enough to solve their own problems : I'd say you are an asshole and a parasite