Do you have 16 boxes?
A boat with even a small leak is going to sink. You, on the other hand, don't need to be perfect to succeed. Imagine that you have a 4 x 4 grid to fill with assets. If it's a business, it might be location, reputation, staff, offerings that are in high demand and a sector that's robust... if you're doing it for yourself, it might include your resume, your network, your skill set, etc.
When someone chooses you or your products, they're considering everything you have to offer. Whether you're looking for a job or trying to make a sale, there is rarely only one thing that makes the difference.
That's why human nature is so enraging. When something is going wrong, when the economy is out of sync, we panic. We obsess about just one of the sixteen boxes and ignore the others. We talk ourselves into hysteria about how, "none of our customers have any money," or, "in this bleak economy, we'll never make a sale." Instead of using the relative downtime to build up the other 15 boxes, we just sit in the corner, keening, worrying about that one box that's out of whack.
By focusing on the red box, the sore one, and ignoring the other elements of what makes our product or career worth marketing, we cause two problems. First, our attention does no good at all on the problem at hand, and second, the other boxes suffer.
The problem with whining is this: human beings like to be right. If you persuade yourself and your friends that times are really tough and that you're bound to fail, you'll probably do the things you need to do to make that true in the long run.