[...] and Android is worse off for it

Hard disagree!

The only damage the whole Nova Launcher thing does is mostly sentimental. Nowadays, there are plenty of launchers to choose from, all with some great degrees of customizability. Here are my top picks:

• Kvaesitso - my current pick. It's not the most flexible on this list, but I generally find more and more ways I could integrate it in my personal life. And the font pick is just great.
• Lucid Launcher - another top pick of mine that is not relied on AOSP. Goes more like a vertical scroll than a horizontal one. Used it on my tablet for as long as it lived, almost.
• KISS Launcher - If you want to Keep It Simple, Stupid. It's all just a search bar. That's it. Search for everything you need and when you're done, you're done.
• Niagara Launcher - also minimalist, but more functional. Didn't really get the hang of it just yet, not sure if I will. Kvaesitso is quite cool.
• AIO Launcher - let's just call it the best strike between minimalist and functional, ok?
• Lens launcher - for when you want to be so minimalist you put all your apps on the home screen
• ap15 launcher - same as Lens but there are only labels instead of icons
• Total launcher - goes the opposite way. Probably the most customizable on this list. Really great once you get the hang of it.
• Square home - if you used a Windows phone, you know what this is about. If you did not, you will know (alternative implementation, Mur)
• Microsoft Launcher - as the name implies, it's Microsoft's current attempt at a phone launcher. Really useful, especially if you are invested in Microsoft's ecosystem.
• Plus there are plenty more others that I didn't get to test really much, such as Smart launcher, Action launcher, hyperion etc. However, the most hyped in this thread seems to be Lawnchair. Looks like it follows Nova the closest among the open source picks.

Really, there's no point in worrying about this. I'm also sad to see Nova go, especially since it was that popular. But there's that. The launcher landscape is the one I worry the less in Android.