For a while now Apple has operated a recycling programme which allows users to take their unwanted devices into their store and recycle them (usually incentivised with a discount a replacement device).
(I don't buy the anecdotal "Nobody can recycle aluminium with glass pressed into it" line from the article.)
It's entirely believable that no-one can recycle aluminium and glass that are glued together in an economically viable way. Apparently one of the major things that dictates how easy something is to recycle is how easy it is to seperate components that are made of different materials.
Maintaining a supply of spare parts for a line of notebooks could very well use more natural resources than maintaining a supply of working laptops for replacement.
(I don't buy the anecdotal "Nobody can recycle aluminium with glass pressed into it" line from the article.)