How then do we think about grief in this culture that extols positivism? If a positive person feels happy, upbeat and cheerful, is a grieving person who is sad, distraught and tearful a negative person?
The answer is no. There is no useful purpose in identifying feelings as positive or negative when describing grief.
The experience of suffering that comes from a loss occurs because an attachment in this life has been broken by death. The feelings of grief are expressions of love, not negativity.