[worldsayshi]

As I see it, pessimism is as "unrational" as optimism. There's a big span of uncertainty about the future that is filled by our intentions and beliefs. If we commit to a pessimistic worldview we are likely to make some decisions that lead towards such a world. If we commit to an optimistic worldview we are likely to get exploited by bad actors.

We have to be able to juggle both realities. That is rational.

(But I think we are essentially saying the same thing here.)