[cosmic_cheese]

Much of the frustration inspired by GNOME/GTK’s unthemability comes down to not having a few very simple knobs for users to tweak. Point in case, one of the primary reasons I used to theme GNOME desktops was to clean up Adwaita’s padding, which is utterly egregious for desktop usage. If GNOME just had a padding slider with 3-5 notches that’d go a long way and wouldn’t impair developers’ ability to build consistent apps in the least. Affordances like these are rarely given however and have to be fought for.

Aside from that, consistency and themability are not at all mutually exclusive. Back in the early days of OS X, theming by hacking system resource files (or patching them in memory via haxies[0]) was quite popular and for the most part, worked very well — generally, the only apps that didn’t play nice with themes were those sitting in the uncanny valley between native and custom, using bits of both, which tended to not be the highest quality applications anyway. This was way before Apple started pushing devs to parameterize their apps, too, and so similar theming capabilities today would work even better since themes can just tweak the parameterized fonts, colors, etc as needed to maintain coherence and usablity.

The real problem with GNOME/GTK is simply that it wasn’t designed with user customization in mind even as a remote possibility. A UI framework that did keep these things in mind combined with a strong dev culture of parametrization would make for a desktop that’s both customizable and consistent.

[0]: https://en.wikipedia.org/wiki/Unsanity

[aecsocket]

Interesting, I didn't know there was a theming presence on OS X! I agree with you in that consistency and themability can exist together (and I suppose your example proves that), and that had GNOME decided to prioritize themability we could have had something like that on the Linux desktop. I suppose this is a question of priority and where to allocate effort, rather than what is technically possible and not. Building a UI framework and HIG is already not an easy task, and making it customizable in the way you describe would be an even bigger burden on developers - many of which are, I assume, doing this work for free. But admittedly I haven't looked much into GNOME's funding or organizational structure, so maybe they are capable of it, but just haven't bothered.