I didn't think you were "attacking" me, but since I'm the only one here talking to you, it seemed you were addressing your feature request to me, and that's not something I can do anything about.
Not a comment about you, but unfortunately it's fairly common for people with questions to mistake the people answering them for JRiver employees, as opposed to strangers doing them a favor, and become indignant if they get an answer they don't like, or the app isn't modified to suit them, or they're not otherwise treated like kings because they're special or have paid their money, etc. So in light of that and your feature request, that's why I said I was just another user, to forestall any possible turn in that direction. A bit of insurance; I hope you can sympathize.
It's been requested before over the years (including by me) to be able to hide things in the tree, but JRiver has never done anything about it, so I wouldn't expect that to happen at this point.
The only other thing I can offer is that you can certainly delete all the existing and default views under Audio, and then create your Music views there. The only difference will be that it's named Audio and not Music, and you can still have your Audiobooks separate, and at least you won't have an "extra" category. If that's not good enough, I don't have anything else I'm afraid.
If you want to make a feature request, probably best to start a new thread with an appropriate title and concisely describe what you want. Something casually mentioned in a question thread like this is less likely to be noticed.
Good luck...