It's not hard to be intellectually honest and negative. Negativity also performs better than optimism on social media.

Much harder to be intellectually honest and optimistic with bias for action, willingness to fail, learn, ability to find the appropriate amount of signal in all feedback and then discard remaining noise, and most importantly, not quitting.

Most of the the time, intellectual people are not optimistic, feels like they know too much of the world. But hey in the end of the day everything is physics laws.