These days, you need to fake optimism in order to get or keep a job. Reality of this industry is that if you hit any hurdle at all during your career... Whether it is your own fault or someone else's, it may trigger a kind of avalanche effect because you won't display quite the same level of extreme optimism that they want to see... Successful people in tech tend to conflate naivety with optimism and see it as a sign…
Granted I work in Silivalley, but I'd say that above a certain level/age, if you don't show a certain base of cynicism in private you're not taken seriously. I mean, if you've seen the dotcom bust, and the 2008 collapse, you're looking at current conditions and asking whether it's worth it right now. The tension on the bubble appears to have exceeded safe parameters.