That's actually the claim made by the original article. As a commenter there points out, though, if it's harder to resell your old machine you may be less like

That's actually the claim made by the original article. As a commenter there points out, though, if it's harder to resell your old machine you may be less likely to upgrade to a new one. So there is pressure in the other direction. The real reason? Apple make more money if you buy from them direct.