Having a specific habit can help push your character into a specific event. It can help them or chase them into a corner.
Good habits sound like they will always be useful, but sometimes a good habit can change into a bad position if it prevents your character from handling the situation the right way.
Giving a good habit can give you fun little quirks and situations during interactions with other people, or give you drama and sensation during tens moments.
And remember: Good Habits can also be bad habits and vice versa.
@RPers, I hope this will help you to understand the reason behind adding a good habit and maybe help you develop a more thought-out character.