Different work cultures have different problems. In bureaucracies, there is often a problem with a culture of "no". New ideas are met with negativity, and objections of "that'll never work" and "that was tried already". However, in the startup world we see the other extreme. Everything is awesome. Every idea is "great" or "disruptive". Teams that obviously don't have what it takes to succeed in the cut-throat marketplace are encouraged and told to "stay positive" and "stick with it". Like most things in life, the answer lies in the middle. But, in this case, the middle path is the one seldom taken.
As a corrective medicine, I am calling upon my fellow entrepreneurs to exercise their negativity--to look for the failure in each of their new initiatives before they even begin. After all, if you want to bend a piece of plastic back to a happy middle position, you need to exert an extreme amount of force in the opposite direction of the current crease. So here's what I propose: I want you and your colleagues to do am mental exercise at the beginning of each new project called a "premortem". Yes, that's right; PRE-mortem, not postmortem.
The idea is to imagine yourself transported into the future, where you'll land at the metaphorical funeral ceremony for your project. There, in front of you, are all of your coworkers, wearing black and with tears in their eyes (for dramatic effect). You land in the center of the group, and console each of them in turn. Finally, you talk about the cause of death. What happened, why it happened, etc. After you're done, reset the situation. Describe an alternate cause of death. Repeat. Write down these histories of the disaster.
This is actually Daniel Kahneman's favorite "de-biasing technique", and was created by psychologist Gary Klein. The purpose is to get rid of the social and organizational pressure to be positive and follow the herd in its quest to release the product and do what has been planned. As Kahneman says, "it legitimizes dissent. It rewards people for being imaginative and finding flaws in the plan". This change of incentives allows a group of people to get beyond the desire to be agreeable, not rock the boat, and be a harmonious member of the team. In short, it destroys groupthink, and allows for criticism and skepticism to flower.
Before you spend any time on a project, you need to be sure to bring the sharp knife of the skeptic up against your plans. I think you'll find that it will cut quite easily. In the land of entrepreneurship, this is a rare practice. But, because of this, it's all the more important.