That comment is just ridiculously biased - you might have a good point, but it's hidden behind the opinion. For example, one could just as legitimately counter with "Apple makes money by developing a desirable brand and overcharging on hardware" but that wouldn't fit your spin, would it?
The Apple lock-in only works as long as the users are happy with their (maybe limited) choice. Apple needs their customers to upgrade to new devices every few years.
How is it overcharging? It's true, their devices are more expensive than the rest of the market, but nothing on the market comes close to Apple's quality and usability. Simply said, they have no competition, so they can set their own price - and while the customers are paying it, it's not overcharging.
Everytime I configure a dell to something equivalent to the analogous Apple product, it comes out about even or about 10% more...and in a hideous plastic casing.
