These seems very childish and anti-competitive by Apple. The real loser here is the consumer who has lost some choice and is being funnelled sheep like towards those products Apple deigns to sanction. The Apple fanboys here will doubtless herald this as a brilliant move by Apple, because it allows them to fill Apple's pockets with more of their money.
Don't be an idiot. Apple stores exist to market and inform about Apple products. The other stuff on the shelf is purely there to fill in space, and generate a few extra alongside sales. Totally ignoring that even in the US and Europe, where Apple store penetration is at its highest, most people have a wide range of consumer electronics stores between themselves and the nearest Apple store, *no-one* is hunting out an Apple store to buy a set of headphones. I can get everything that is available in the Apple store at my local BestBuys, or HHGreggs, and with a lot more options at better prices. Even Target and Walmart offer most of the range.
Pretty much the only thing that Mac stores stock that you can't easily find elsewhere is Mac software, and with the Mac App Store, who cares?
No choice is being lost anywhere. Apple is a boutique store, it is in no-way equivalent to BestBuy or Dixons etc, and it's entirely Apple's prerogative to stock whatever they so choose.