I don't think questions should be closed because they might turn argumentative, better to wait and see what develops (and trounce on it quickly if it does spark up). It's on the edges and fringes where interesting things happen and learning takes place.
For example I think the question on ArcGIS Server vs Open Source had great potential. It would be very useful and interesting to know when and why people are choosing one platform over the other, and is a central and recurring issue for many of us. Yes "propietary vs open" style questions can easily slip into he said/she said unproductive debates, but it doesn't have to go that way, and in this example it didn't. The question is not very good, but the answers given to date are good.
I think the asker should have been given more time to respond to the criticism before closing the question. 1 day is too short.