The author tries to link the fact that people would like to see data portability in cloud computing to the success of consumer stuff like the iphone and the like.
They are completely different beasts and you can't compare them like that.
As for the closing question: "Has the possibility of “vendor lock-in” ever stopped you from making a purchasing decision or is it just a “potential risk” that’s weighed in the overall decision making process?"
Yes, every time. And unless the product has very limited utility for me (say facebook or something like that) I refuse to put myself in to a position of 'lock-in' because experience has taught me that it is only a matter of time before the thumb screws come out.
So even 'free'+'lock-in' won't cut it for me.