When it comes to computing, it seems to me that most people would rather have a pretty prison than freedom.
Freedom for 0.1% does not trump freedom for the masses and RMS is just engaging in shameless self-promotion.
You can have freedom to install what you want, the way you want... only a minority ultimately knows how to. The rest is left without a clue in front of their supposed freedom.
When the iPad is presented to people, of course it's no "revolution" to most of us. But for the regular person, it's an easy way to access something which they could have had difficulties to access, before. At this point, choice matters less than the actual possibility to use something, even if this thing is framed and safely guarded, for most.
Better not let your important data get locked up in any non-portable formats though. A literal prison is far easier to release someone from.
And yes, important data should not be locked in non-portable formats. At the same time, I've never found myself in a situation where I simply could not extract important data from a non-portable format into a more portable one.