Honestly, the biggest gripe I have about the App Library...can/would be solved by developers reevaluating how they categorize their apps. Off the top of my head, an app that comes to mind is NurseGrid (for my work schedule). It's in the "Health & Fitness" category. I think it would make more sense in "Productivity" or "Utilities".
I also have stargazing apps. Some in the "Education" category...some in "Information & Reading". Though I can't decide which of those two categories would make more sense for that type of app.
I don't hate the App Library. I just think it can be improved by some "re-categorization" on the part of a developer. I'm assuming that doesn't require a lot of work from the developer, but I'm not one, so I could be wrong!