Answer: That he is disappointed in humans behavior
Step-by-step explanation:
This excerpt and thoughts of Frankenstein are showing the readers that he does not know what to do if someone is having bad behavior towards him. He is aware that there are people who are not kind to others even if they don't have reasons to act like that.
He is telling the readers that he will be good for everyone who is good to him and if he cannot inspire love then he will cause fear because he does not want anyone to condemns him.
He does not understand why someone would be unkind.