Some Windows users that I know (not power users in any sense) state that they do not migrate to Linux because, as they say, "the OS is different". Of course, they never consider that they had to adapt from XP to Vista and then to 7...(One wonders what they will say after buying a computer with Windows 8).
They also claim familiarity problems about the software that they use to create documents, chat, or, in extreme cases, to log into their Facebook accounts (?!).
Basically, all these arguments can be reduced to a sigle issue: adaptation.
However, I believe that there is more to it. Adaptation, in the case of using a computer, requires an act of will; the user must be willing to abandon the comfort zone and begin to learn. This challenge, far from reducing one's productivity, increases it in the long run because intellectual numbing does not make you a better worker. It only gives you an illusion of efficiency.
I have two cases to support my observations.
1. A tale of a PC and a phone
My mother, who is in her sixties, took Windows courses hoping not to be left behind in the digital divide. However, much to her distress, very little that she learned was applicable once MS Office 2007 replaced MS Office 2003. The learning curve was pronounced thanks to the Ribbon interface, but, in truth, her real problem was viruses: she was terrified to use the computer because it got infected thanks to her friends' USB drives, emails, etc.
When my brother Megatotoro replaced Windows XP with Pardus 2009, she started using the computer freely. Then she bought a new, more powerful machine and now uses Pardus 2011. I haven't heard any usability complaints from her. In fact, she proudly tells me of her new records in the games she likes.
In addition, she recently bought a new cell-phone after having used the same one for almost 15 years. This new phone has Android, which replaces the old, familiar buttons with-- a tactile interface!
Yes, she got freaked out a little. However, I'm sure her determination and her previous experience switching OSs will help her master her droid.
2. A laptop and its OS
My wife loved her Toshiba Satellite laptop running Mandriva 2009 but she got a bit sad when she asked me about using Skype to have video conferences with friends.
I told her that, even if she had to forget about Skype, there was still Google Talk for that particular purpose. The problem was that Google Talk did not run in her old OS. The solution: migrating to Mageia 2.
This is no trivial change: after booting and updating, you have a new version of KDE (4..8.5), different icons, different names for things and there's even that Activities thingy that obviously did not exist in KDE 4.1.2....
Yesterday, I saw her working with her laptop, a rather familiar sight, so I went into my office to read. After an hour had passed, I remebered that she was using a completely new OS!
I stepped quickly into the room where she was to offer assistance. Interestingly, all the normal body cues that manifest human frustration were absent from her; she seemed to glide as she was working and turned to me with a smile when she noticed my stare.
From these two experiences, I conclude that adaptation is not the problem. The real issue at stake is the lack of will to adapt; both my wife and my mother learned how to use their devices because they wanted to use them. And they wanted it badly. It had nothing to do with the complexity/ applications/ interfaces.
I guess that also explains why my brother and I, two heavy Windows users, migrated to Linux so successfully by ourselves, despite no one ever introduced the OS to us or helped us ease the transition.