> but my fairly non-technical wife has a Cricut and the few times I've wanted to use it I had absolutely no problem

This is this is one of those situations of knowing their audience. The machine is nice and does some impressive things for the price. Their software works fine for the people that the hardware was designed.

I too have designed things in Illustrator and imported them into their software. It took a bit of getting used to, but I've designed retail packaging with cuts and scores so I can create custom boxes that I was not able to find premade and having the custom design made was too expensive. Could the design software be better? Of course, but that software would be out of reach for their target audience. So instead, I've stopped holding it wrong, and work within its constraints.