I’d avoid the construction/engineering/architecture/interior design metaphor. In building design (say, a simple commercial building) there are legally defined boundaries as to who designs what — architects can’t get an engineering stamp and engineers can’t act as interior architects etc. And the construction firm builds the building with a completely different toolset than all of them! Wish we had laws like this for software designers and engineers ;)
Personal experience: even when I studied architecture in college, we didn’t initially learn CAD. We were line drawing on Mylar, sketching on paper a lot and 3D modeling and animating in completely different (easier to use) tools than AutoCAD. Even today’s star-chitects don’t touch AutoCAD or the myriad of construction management software tools that are out there. In other words there are clearly defined roles and great tool sets for everyone. Yes, AutoCAD is a standard, and it’s awesome you are trying to create something similar for software design, but you’ll never rid the designer of their need for a simple tool to create low fidelity design.
Designers often start with rudimentary tools …they’ll improve on fidelity after testing and assessment. This has been the case with architects from Ancient Greece to today’s visual designers. There’s a reason why illustrator or photoshop aren’t the in vogue UI design tools, they aren’t nimble or fast. Designers often require speed, and typically they pull out code from the equation to achieve that.
Oh, btw you’re right that Sketch isn’t a UX tool, it’s a UI tool. You don’t really understand interface design yet if you are interchanging the two terms! Ahem: