Also, sometimes an application can take longer to process because the applicant missed little things, like a signature, incorrect or missing information, etc.
Take for example, the two people on this thread who don't like the longer processing times. One of them didn't realize that if you paid your RPRF fee upfront, you can speed up your application, if she had read all the instructions carefully she would've seen it.
And the other one made the mistake of hiring a lawyer who gives bad advice, such as telling him that he shouldn't order GCMS notes because it might delay his application. If he hired a better lawyer, maybe he would've been able to help him submit a better application and avoid the interview that he eventually got, but thank god he passed the interview at least.