I have a bit of a quibble with this point: "CAD is genuinely difficult." When I was in the university and had access to SolidWorks, it took me less than ten hours to design something that was moderately complex. Eight years later, when I tried to design something for my side project using cheap and free 3D CAD programs, I had the hardest time doing so because the programs I tried were simply not powerful enough. The problem is not the CAD concept, it's the programs. There's no reason why CAD can't be easier than ever, and it might be if you purchase a multi-thousand dollar program.
Honestly, my concern is that something like the GIMP will take over in the open-source CAD space, and stymy efforts for making something as useful and powerful as Solidworks. We've seen this happen before--let's try to avoid it.
There is: FreeCAD, based on the OpenCASCADE kernel.
SolidWorks is just so easy to pirate, that no one has much motivation. It's a massive effort to build something like this.
Also, it requires a multi-disciplinary team: math, programming, MechE / ID, UX, etc. - it'd be hard for an open source project to do this without some type of funded entity.
I agree. A great example of a "CAD tool" that lets you design complex, believable organic creatures easily is Spore Creature Creator [1]. It's easy to imagine similar kinds of tools for many other object types.
Totally, if you're motivated you can get SolidWorks do give you good output in days or even hours. I've heard some are worse at 3D visualization, so maybe we're outliers, but I doubt it.
