To hold a grudge speaks nothing of why the grudge exists in the first place. Regardless of type, if someone has hurt you repeatedly, it is okay to feel hurt, anger, hatred, or resentment. One can be too quick or too slow to hold a grudge, but everyone has a threshold and everyone is capable of having one. One thing is for sure though, it will tear you up inside and eat away at the heart of your existence, whether the grudge is justified or not. I have held a few grudges in my life, but they stemmed from years of hurt that slowly evolved into a grudges over time. Usually, I approach relationships in a shy, yet open manner, and will easily forgive for most acts that cause hurt. It is only when it goes on for quite some time and the person seems indifferent to how I feel at all when a grudge starts to take hold. If there is a lot of hurt, I will eventually cut the person out of my life, but I always hold out for some sort of reconciliation. When they ask for forgiveness, I tend to forgive but not forget, so the relationships can revert back to its previous state quicker than with new relationships.
I think issues such as grudges are too complicated to reduce or attribute to any type and are all a part of being human.