There’s no such thing as a “rational emotion”. Either you’re rational about something (i.e. consider all facts and weigh your decision calmly) or you’re emotional and go with gut feelings.
Hate is NEVER a good adviser. It makes us behave irrationally and usually in a destructive manner. It is never constructive. It is even bad for yourself. You suffer from your own hate, and the more hate you harbor the more it will consume you. If you don’t believe me just read up on this subject, mental health websites are full of analyses on this.
I would go so far as saying you are NOT entitled to hate someone, because it leads you to project your destructiveness outwards into your environment and you cause pain and suffering to others. Ever heard of hate crimes? They are essentially an enactment of your destructiveness out onto others. We call these crimes because in our Western societies we’ve moved on from the days of “righteous vengeance”. If you want to see what uninhibited hate does to communities, take a look at places like Syria, Iraq, Afghanistan, Pakistan… this is not the kind of society I want to live in.