I agree it is healthy to access and honor negative feelings, but only to a point.

It's more along the lines of "Okay, this hurts, I acknowledge the hurt and carry on anyway".

It's a huge mistake (I think) to succumb to the negative. It must not dominate.

It's a skill not to do so, and like any skill is requires self-discipline and much trial and error before mastery.

But, I really really do think it is worth it. I really doubt on their death beds anyone would say, "I really wish I had spent more time allowing negative emotions".