Whoever closed those threads would have to state his or her reasoning for doing so (I'm not familiar with the threads in question), but different mods have different perspectives on things, of course. The more controversial threads tend to go off rail quicker, and usually end no where good. At a certain point, they almost inevitably get closed, if not by a mod then by Dave himself.
I do find it to be helpful to post something when I close a thread so folks know I did it along with some kind of rationale, even if it isn't very detailed. Then, folks can (and often do) PM me about it if they have issues and I can explain my reasoning. While I would love to have more open discussions on serious and controversial topics (religion, politics, NECA vs. Hot Toys), it just doesn't seem to work here in most cases.