Just because you focus on the good doesn’t mean the bad doesn’t exist.
If there’s a hurricane headed towards your hometown you don’t just focus on the good hoping the bad storm doesn’t exist. You account for the good and let it lead you away from the bad. You respect the bad but you don’t dwell in it.
“Focus on the good.” is advice that shouldn’t be taken at face value. You have to respect the opposing force. Only then is your focus on good a solid stance.