I mean, to take an extreme example: the Holocaust. Yes it eventually ended, but the damage was massive. The people who were in concentration camps didn't have the luxury of just riding it out and knowing things will get better.

I understand that people can come together, but there are also people with more negative views and intentions coming together as well. There may come a time when you need to fight for what you believe in or even flee for safety. Unrealistic optimism can lead people into a very false sense of security by building a bubble that's is oblivious to an impending event that could impact them.

The storm may pass, but people may die. Telling those people now that everything will eventually be ok is doing them a disservice.