I just ran across this proposal for imporving the UI of Blender. First of all it is nice that they are trying to improving one of the most confusing an not intuitive interface I have come across. It is especially also nice since they also recognized some design flaws, like having to set object properties before creating the actual object, which prevents adjusting the properties afterwards.
Another interesting point is to see how it could come that far; Blender was initially intended to be used by the same people who wrote it, which is a small audience that does not care about usability and interface standards, so you can define the UI the way you like it best. But as Blender became opensource the audience dramatically increased and Blender now is used in the context of a desktop, where standards matter.
But what I do not like is the way out of their “self written toolkit” trap; first of all the proposal says, that it is a good idea, that Blender looks the same across the platforms. But that is clearly a false assumption since meanwhile we know that “same everywhere” translates to “integrated nowhere” – this is even something that Mozilla after a lot of struggling acclaimed when they left out their key-lock concept out of firefox3 on Linux. This is also a principle all modern cross platform toolkits try to follow, but Blender wants to keep to its own look, which they want to improve instead.
This shows another problem of the “self written toolkit”; currently they have many problems with usability, because the toolkit is broken at a basic level, like there is no visual difference between buttons and a one out of many selection. Things that were available in GTK for years and which are documented in the HIG, so you can use them correctly.
So basically what we are seeing here is another lack of interaction between Open Source projects – instead of use (for instance) GTK and get platform integration and the experience of years with user interaction for free, Blender tries to fix their inherently broken toolkit and so to say reinvent the Wheel.