You got to remember, "instant gratification" is the ticket these days.
If it requires time and effort, it ain't worth doing.
I suspect this character flaw is a requirement for Mac dweebs.
Good general consumer devices/software should be impressive from the beginning. At least it should be easy and intuitive for most basic tasks, and preferably be pleasant and inviting to use. The user experience should be seamlessly integrated.
20 minutes is plenty of time to decide one doesn't like it. If it isn't, then by definition the product doesn't pass the above simple tests. I know within seconds whether I like the handling in a car on a test drive. The dealer telling me that I can learn how to use the cool automated cupholders and such in another 30 minutes isn't going to help.
Apple has this concept, Microsoft and Linux don't. The iPod dominates because it was the first mp3 player to have this concept. OS X is growing because it does.
I'm not going to go full resume, but let's just say that HCI has been a big part of my professional life for about 10 years.