Drifting apart

Why is it that people in romantic relationships cannot drift apart from time to time? Friends and family members drift apart all of the time. Everyone has their own path to follow and their own lives to live. Why is it that if this happens in a romantic relationship, that it must come to an end forever? I’d never cut a friend out of my life just because we’re in complete different places. I wish people viewed relationships in the same way. The spiritual connection and love you feel for that person should be strong enough for you to be able to let go of  them from time to time. There would be a lot less heartbroken people in this world if romantic relationships were treated and viewed in the same manner as any other relationship.