If you don't do that it's easy for your idea of what something is to morph into something sexy that's the best thing since sliced bread. Also it's a function of non technical people having a brainstorming session. They pat each other on the back for taking this thing to the next level, which is actually the previous level.
The problem is in the corporate world there is no trust. People seem to get the notion that if you use facts to show them their idea is bad that it is some sort of personal attack. Or worse, there are those in the corporate world that can spot a bad idea and not say anything -- only to watch it fail.
Even without that, its a confounding problem for me. Im always doing those things: asking questions either to genuinely learn or to ferret out possible mistakes, pointing out errors, sharing better methods/techniques, etc. I just cant help it, and while I try hard to word things in a constructive manner, to make sure it IS constructive, more often than not I think it is taken poorly.
I want the same criticism of my own work, but I still often have a difficult time with it myself, though I recognize the signs as the knee-jerk reactions that they usually are, and seem to get better at that every day.