This is a bit of a nirvana fallacy issue. The Next-like window manager family wasn't sold on purely visual merits, and thus even just having the window managers

This is a bit of a nirvana fallacy issue. The Next-like window manager family wasn't sold on purely visual merits, and thus even just having the window managers themselves provided some benefit. I don't see that as much in the Aqua-likes, as the functional changes are pretty minimal (scroll-bar buttons on the same side, back when that still was a thing) or even counter-productive (keeping all the window buttons together). Back when bowman/afterstep/wmaker came out, pretty much no one who used them was familiar with the NeXt interface, beyond having seen one in a magazine or knowing its look-and-feel via Win95 copying some of it. As far as I can remember, the popularity rested on a few pillars: For one, it's a pretty sleek look compared to twm or mwm. It also had a rather good resize functionality -- big enough handles to grab at the bottom, while saving a few valuable pixels at the sides. A lot of people also like(d) the dock apps that came with it. Even other window managers adopted them. Can't say a lot about general dock/shelf usage, as I never got into that. Window shading was nice and probably introduced into common usage by that family of WMs.