First time CAD users have to learn a complicated set of actions to even begin to be able to draw an object. The problem with CAD programs is that they all seem to start from what the CAD program wants to do (draw lines and shapes like cubes and cylinders) rather than starting from the picture in the user's mind.
If you do a lot of 3D printing, you will experience continuous challenges with this approach. First, many people do not draw well. Second, most are not fluent in CAD. Third, most people don’t want to spend months becoming fluent in CAD. They do nonetheless want to be able to create objects, express their ideas visually and 3D print some of them. I believe there is a big universe of people who would like to draw / make / create, but who can't because of these challenges.
I suggest that we approach the problem by turning the system on its head, by starting with what the user has in mind. Translate the picture from their mind and their words into language that the computer and CAD program can understand and manipulate. Importantly, to speed up the process, start with a 3D object that serves as a template or jumping off point. I call that template a "digital analogue." I really like that term, which probably says a lot about me.