I would argue that any pessimism that doesn't fall into nihilism must be inherently hopeful

Pessimism acknowledges, as the piece said, that sometimes it is OK not to be OK. And that we don't gave to pretend that we are or will be in order for our worldview to make sense

The reason I have rejected optimism is the same reason that I have rejected Christianity. Both seem to say that righteous, wrathful rage should never be the appropriate response. And that whenever something good does happen, then that is the natural way of the world, or God's plan, instead of a violent departure from the normal state of many of our lives. Neither of these paired attitudes offer a realistic or useful view of reality as it is. They are only marginally useful as a view of how reality ought to be.