The problem we have here is that in Islam we are supposed to love and hate for the sake of Allaah. Yes, you can love and hate some for personal selfish reasons but if they are outside the guidance and guild lines of Islam, then it’s not necessarily sanctioned. A few examples to clarify.

1) Some ideas are evil, and repugnant, but if I hated someone specifically just for that you may assume that this would justify all sorts of mistreatment. That’s normal for ‘hatred’. But in Islam we’re ordered to guide such people to righteousness and good behaviour, deed and beliefs. Why would you put effort to help someone if you “hated them”?  That shows that it’s not the type of ‘hate’ you’re thinking of.

2) Likewise, you love someone, but only to a point whereby you don’t commit sinful deeds or mistreatment of anyone because of it. So if I was madly in love with a woman and she told me I must rob someone so i could get her some expensive ring, that love would be wrong and forbidden if it leads me to such a sin. Likewise, if would be prohibited for me to aid any fellow Muslims to oppress a non-Muslims, and in fact I am obligated to stop him. So although my aligences is towards my fellow Muslim, I cannot let that ‘love’ lead to sin. That’s not really love. The prophet Muhammad said: “Help your brother, whether he is oppressed or the oppressor”. His disciples said “we understand how to help him if he is oppressed, but how can we help him if he is an oppressor?” And said “stop him from his oppression”. 

So when I say “hate someone for their idea” it’s not the same type of hatred a racist has for ‘the other’ for example. 

So bringing it back to the original conversation. If I met someone who had no issue in the murder of innocent civilians , or they agreed with the use of nuclear bombs on civilians, I very easily hate that person for having it in them to accept such barbarism, but if I was able to get them to change their views through dialogue, and they changed, I would have zero reason to hate him further and in fact I would love him for his sincerity and goodness. 

 The hypocrisy of the last sentence.