Steve, I like to look at pictures of God's creation too. And I am as interested in people's testimonies as the next guy. I wish there were more, actually. But when somebody tells a joke, we are not asked to pray and seek God for the punchline. If somebody saw the face of the Virgin Mary in their omellete, then who am I to argue? But am I to pray and ask God to show ME the sign and the meaning behind it? Should I leave them to continue following after signs if it's in my grasp to influence them differently?
At times, there are posts that elicit discussion and different points of view can be expressed as to what this means to each of us individually. Craig's post on the observation of the differences between 1957 and 2009 is a good example. That's what people do when they talk. We can take it or leave it, add to it or disagree with it. If it interests us at all, it makes us think. If Craig had started that post with the implication that he had some hidden wisdom not in Scripture that we ought to be praying and asking God for, my reaction would have been the same--expressed or not expressed.
There are also instances where from the post itself, it seems clear that the member is losing focus (or has never had it in the first place) on what is important. To rock or not to rock is not important, ultimately, for an example. If moved, we should attempt to raise the bar to that higher calling--otherwise, all we have is our own opinion and 'testimony'...both of which may be fine for you but not a 'religion' that others must follow, and leave the OP as much in the dark as when he or she asked.
It's a fine line between Godly council and spiritual one-upsmanship, but I don't think it has been crossed here.
That's the take on 'why' from my chair.