Bah, the guy's full of it. The Fire and new Kindles are no different than the previous ones. The average person will buy them and use them and buy books and movies and music from Amazon for the convenience, the support (nobody beats Amazon in that department) and selection. End of story. The kindle format is already "locked in" so that will keep the average person in their camp, but it really doesn't matter because the average person doesn't care as long as Amazon supplies the book, movie, music they want. And with the Library loans, they are set.
Sure the more tech-savy will root their Fires and Kindles and to do additional things with them but it'll be in the noise as far as the business model goes.
Amazon will continue to kick butt.
P.S. and just for the record, I own a Kindle2 but rarely use it, yet I buy virtually all my books from Amazon. Now I may be an anomaly but I doubt it. And that is exactly opposite of what that guy claims and you seem to have swallowed whole.