Li Feng didn't deliver any passionate speeches, as they're meaningless. For these people before him, staying wasn't because they believed in Li Feng's future; rather, they simply had no other options.
Li Feng returned their life contracts to them, but these people had lived in places like the Duel Arena for so long, they were disconnected from the outside world. What was taught in such a place were killing techniques and obedience.
In other words, these war slaves before him had been brainwashed, accustomed to following orders, and given the big environment of Ancestor Dragon City, even if they were truly free, they wouldn't know what to do in the future.
Don't forget, Li Feng is a master of psychology, and having served as the Dragon King for so many years, having traveled the world, he has seen many forces, many of which train soldiers using methods like these, utilizing spirit control to make them into self-destructive tools.
