To dislike someone or something is at least honest

Indifference and neglect often do much more damage than outright dislike.  J.K. Rowling

At least with dislike we are feeling something.  When we are indifferent and neglectful that usually means we have fallen into numbness, i.e. we no longer care.  And complacency does much more damage than feeling something.  Complacency leads to lying, neglect (which causes a lot of damage - just look at the homes of hoarders where they have neglected the upkeep), isolation, unwillingness to engage in life, delusion, etc.  Those are all damaging.  But when we are honest about what we are feeling (i.e. "I dislike that person") we are at least allowing feelings to have their voice.  That's the other thing indifference and neglect do, they shut up the voices of feelings.  And shutting up our feelings always leads to great damage.  So dislike if you must but don't become indifferent and neglectful because the damage will be so much greater.