I think you mean unfamiliar, with a long learning curve. Yes, but they also went the extra mile and made sure it couldn't really be pushed farther without their permission. That's easy. You pick frequently used functions and put shiny buttons in places for people to poke. The trick is getting them to do this (which Nokia did decently well on the N900) without going the extra step and ensuring the user can go no further. A phone running Linux is no different from any other phone, provided the UI is done right. But the UI isn't really the problem with the N900, it's Nokia's execution and follow through that is the real problem.