My favourite genre of meeting: We have a problem to solve, we get to a solution fairly quickly, but then we go on a little jaunt through various complex and unworkable solutions before landing on the same original solution.
I don't think that whole process is totally worthless; it gets the questions out in the open and irons out edge-cases-that-aren't-real. It also gives the contrarians their platform (there are few things I dislike more than 'devils advocate').
My position usually comes back to not really caring as long as we remain consistent, but the simplest solution without trying to crystal-ball future problems is the one to go for.