Get Luffy 's invitation to crew.

I found something interesting about Luffy.
Luffy only invites those who are outcasts from society and alone .
Ussop the Liar
Robin the demon child
NAMI the cat bugler,
Sanji the failed project
Broke the only survivor in whole last crew
Jinbe outcast from mermaid kingdom
Zoro hunts pirates solo
Do you agree with me

( If there any error in my English, please forgave me. It's not mother language, that why it's bad)