Why is Inkwell stuck in review (opens in new tab)

I submitted Inkwell for iOS to Apple for review on April 21st. It has gone through numerous rejections, code changes, resubmissions, clarifications, one phone call, and one appeal to the review board, which I’m still waiting to hear back on. What’s the hold up? I’ve hinted at some of the issues, but I’ve tried hard to be patient with Apple, so I’ve mostly kept my mouth shut while waiting. I’m getting discouraged, though, so it’s time to lay out the problems here, organized by App Review Guide...