As an American, I think there are two sides to this coin. On the one hand we have various (annoying) forms of forced positivity. American cheerleader culture is one, the cult of PMA (Positive Mental Attitude) is another, and similar things. It’s like some of us think the natural state of humans is to be overtly happy all the time, and if you’re not you’re deviant.
On the other hand though, toxicity is worth avoiding. It can ruin team dynamics, and turn a high-functioning org into a backstabbing dysfunctional one. For instance, one wise thing Joe Biden did at the start of his term was to require that everyone in his administration be nice to each other, treat their colleagues with respect and dignity [1]. He was preemptively killing toxicity before it could emerge. HN enforces this too as a matter of policy.
You can of course have the latter without the former. And criticism can be constructive and honest without being overtly cheery. (The Japanese are good at this fwiw - “Fix the problem not the blame”). But some Americans, subcultures, and corporate cultures, don’t always understand the distinction and mix them up. And some business people believe that happy workers are more productive, and so encourage positivity for that reason, even though studies on the subject have long produced mixed results.
[1]:https://www.foxnews.com/politics/biden-administration-be-nic...