Please, please, please don’t use a GUI toolkit like this, that draws its own widgets rather than using platform standard ones, when developing a plugin for a digital audio workstation (e.g. VST or Audio Unit), as this author is apparently doing. Unless someone puts in all the extra effort to implement platform-specific accessibility APIs for said toolkit. Inaccessible DAW plugins are a problem for blind musicians and…
> but really, what’s more important, code aesthetics or usability?
Well, if you want software developers to write using it, code aesthetics is pretty important. Code aesthetics is usability to software developers. End-user usability does tend to trump code aesthetics if you want to get money out of the software you write, but even then, code aesthetics is still a consideration.