I believe the backed up que is more about an increase in the number of contributors, there are more and more people joining the different sites. A lot of these people are hobbiest who need to learn the tricks of the trade. The increased number of contributers run into he one bottleneck on any site which is the inspection process. This is because that is the one place that is people intensive, there is no computer program than can decide if a photo meets the standards.

We are in some respects victims of our own success. More contributors, many who need have go through the learning curve, means a bottleneck that I suspect will not go away for a long time. More contributors also mean more rejections.