I think short question OPs are perfectly fine. Simple questions force you to address the framing of the question. With a longer OP, you run the risk of herding the thread in a certain direction. Besides, a lot of these short-form OPs have had a good amount of discussion in them. The question is just a starting point, and as we've seen in the thread themselves, they head down one direction or another. I'd say that an extensive OP is hardly necessary if the discussion is going to develop well anyways. And they haven't burned down in flames yet, which is a lot more than we could say one or two years ago.
All that really matters are the results. Does the depth of the OP affect the amount and quality of the discussion that we see in RT? If short-form OPs are providing a good amount and quality of discussion, then they should stay and there isn't much to criticize them for. Could long-form OPs be an improvement? Absolutely, especially for topics where there is a high information barrier to posting - take global warming or the intervention against ISIS for example. But for threads about sexual orientation, gender, and abortion, for example, I think the average person is reasonably familiar with the topic.
All that really matters are the results. Does the depth of the OP affect the amount and quality of the discussion that we see in RT? If short-form OPs are providing a good amount and quality of discussion, then they should stay and there isn't much to criticize them for. Could long-form OPs be an improvement? Absolutely, especially for topics where there is a high information barrier to posting - take global warming or the intervention against ISIS for example. But for threads about sexual orientation, gender, and abortion, for example, I think the average person is reasonably familiar with the topic.