@Gothix Sorry man but what are you saying is good only on paper: you cannot force the majority of players to just avoid to group up because you think that in that way they are carebears.
As you said, people will almost always search for the fast and easy solution and in a sandbox game being a member of a massive guild is the way.
In the end it's in the hand of the Devs: do they want Fractured to be a game where few massive guilds fight between them or where you have tons of little group trying to gain control of local resources? Whatever choice they'll make, someone will be pleased and someone else will not so everything is just all down on what they want to game to be.