As awesome as it feels to have someone agree with our every thought, it can be a very dangerous thing. Nobody's right about everything, and nobody's ever right all the time.
We all need a dose of objectivity. Of course being fully committed to a project is the best way to see it succeed, but sometimes we have to step away and look at it with fresh eyes, and sometimes those eyes shouldn't be in our heads.
When we're envisioning a goal we're seeing the end-result in its ideal form, but that's before we've gotten down to the actual creation process. Sometimes there are obstacles we can't overcome, we tweak, we adapt, and slowly the project drifts from our original concept. There's nothing wrong with that, some incredible masterpieces are the result of 'happy accidents.' Sometimes obstacles are there for a very good reason.
If we let ourselves get too obsessed with things being a certain way and they don't play out like that, we can get extremely frustrated or blind to their imperfections, and after pouring our blood sweat and tears into a project, we certainly don't want to hear anyone point out its flaws.
Too many people hire staffs of 'yes men.' When someone's on your payroll they already feel compelled to agree with you, lest they get fired, they rely on you for their livelihood and that's something they don't want to risk.
So, if you launch your project from a vacuum you'll probably be very shocked by negative criticism, and possibly very angry. You might blame everyone else because it makes sense that one who won't consider dissent, won't consider him/herself at fault either. The only way to avoid the humiliation of an ill-received idea is to apply objectivity.
It gets harder to create after you suffer a failure, it's no reason to give up, but it is reason to re-think your process - don't believe me? Just as Chris Gaines.
P.S. If you're a Yes-Man and the project you championed against your better judgment fails, you're probably going to be fired anyways, so, why not err on the side of dignity?