The issue is that these tools are used in day in and day out by a specific audience that is willing to make the investment to surpass the bad parts of the UX. It's not like a 3D artist can choose to skip using a 3d package - and in many cases the choice which one will also be dictated by external factors. Once the initial hurdles are surpassed, the UX of the tools does work well for that flow. It has to, because that's the customer base.
Basically, these tools can afford to suck in the basic UX because they can't really "bounce" users there.
I do believe that by that metric Blender UI is not that bad.
How do we design effective UI's for 'pro' users?
At what point is an application 'pro' enough that it requires a couple hours and some video tutorials or a user's manual to actually get a sense of how the tool works, versus how much effort should be put in on the developer's part to make it 'intuitive'?
Consider what your aspiring aviator sees: http://i.imgur.com/bRmpbjg.jpg
You can dumb that down, but you put people in danger if you do. Burying rarely used things beneath a layer of abstraction is fine in the case of consumer software, but for a pro that might be a huge hassle, or even a dangerous liability in the case of a plane. Engines don't catch on fire often, but if the controls to shut them down involve six tedious steps (Preferences, Engines, Advanced, Shut-Down, Next, Confirm) instead of one quick tug of a lever that could be disaster.
Since most people here are programmers: some will love VI. VI has an awful interface for beginners. It's incredibly fast once you get used to it.
Since I've learned how to use both VI and Blender, I'd say that Blender is the VI for artists. The interface is great to work with, once you get past the initial steep learning curve.
>it has a API made of Shortcuts.
That... makes no sense. At all.
>A good User-Interface is something that adheres to a common users expectations of the virtual world.
So, because it has a bad UI, it had no UI? That doesn't make any sense. Just because a UI is bad doesn't mean it's nonexistant.
Building a good 3D modeling package UI is really difficult. Just look at MAX, Maya and MODO. Blender isn't really much worse. Some consider it better.