Hate is not non productive. Hate, like any emotion, can be a motivating force, and in this case, an extremely powerful one. When soldiers go to war, they fight harder if they hate the enemy. A District Attorney will work harder at his job if he hates crime. Some people, hating that they have been belittled or ridiculed, have been motivated to achieve true greatness. So, it most certainly can be very productive, even if many times, it is pointless.
I hate Satan, and his schemes, so I struggle against them more vigorously. Is that mean and negative?
In my opinion, expressions of hate cheapen FR, and that bothers me.