I think it is incredibly arrogant when someone represents themselves as KNOWING exactly what God intended when it comes to "gray" areas, or subjects that are vaguely addressed, or not mentioned at all in the Bible. A couple of topics that seem to get a lot of thread around here; masturbation, secular v. Christian music, are examples. Just about everything in the Theology forum it seems.
On the other hand, there are some topics on which the Bible is clear and straightforward, yet folks seem to want to paint them gray, as fits their needs (wants). I would list divorce under this category.
So, in answer to your question, I would say that, on topics in this first paragraph, while ignoring them may not be the absolute best option, it may be in YOUR best interest to do so, depending on how you respond to it. For instance, I rarely visit the Creation v Evolution boards anymore because I get angry, I begin to question my own position, in an unhealthy way, and it does nothing to strengthen my relationship with Christ, so I stay away from those debates.
The second set of topics on the other hand, I think should be debated if someone decides to take a position clearly against what is outlined in the Bible. Technically, there SHOULD BE NO debate, because we should all be reading the same thing, butwe know that doesn't always happen.