I'm speculating that this change is the result of analyzing their users' behavior. Over the past couple of years I made a switch to asking questions, especially when trying to figure out some obscure Excel code I needed or something like that. I almost always found some forum response that would answer my question relatively quickly. I'm curious to see how this change will effect the results compared to my past experience. This might prove to be a boon for sites like Quora, as well.