There's a healthy balance. Some of the best things that I've learned here, came from discussions that stemmed from "what if" scenarios. They're also a good way to identify the uniformed and nudge them back on track before somebody gets hurt.
That said, not all "what if" scenarios are equal. In fact, there are some occasional flat-stupid ones that sound like they came from an over-caffeinated 14-yr-old.
Given the stated extremes, I'll still read through and comment on most.