> Having myself let regular users (who don't visit technical website and such) play with Gnome Shell running laptop, neither of them complaining about usability, majority of them already familiar with cellphone interface and few of them never touched a computer in their lifetime. Reading some posts, it appears the complains are from those who heavily optimized their desktop environments.
IMHO It seems like you are fooling yourself. Honestly.
You should try:
1. handling a "vanilla Gnome install" laptop to someone else,
2. have that person give the laptop to this 'test user' of yours and *leave*
3. while you are far and away from the scene (hopefully monitoring through camera feedback).
1. Just the fact that a "knowledgeable user" is sitting next already improves the experience as it calms people down. Anything goes wrong, the life-guard is right next to you.
2. I assume that once a user doubts about something, it will look at you. Say, if the mouse is going to the right direction, you'll confirm it before you know it. If its the wrong direction, you will guide them (perhaps by just glancing into the right direction, or frowning to indicate that the user should stop and reevaluate).
My experience is that teaching older family members 'new tricks' (how to deal with new interfaces, or solve new problems) while sitting next to them is trivial. I could almost say, "they figure it out by themselves". Remove me from the room and place me on the phone trying to guide them, and we have nothing but frustration.