As the article mentions, it's not obvious what value iBeacons provide compared to direct audio/visual information. For the same reason QR codes never took off. Ever since QR came into existence I haven't seen a single person who'd voluntarily scan a code (or an NFC label for that matter) in the street, anywhere in the world.
Clearly iBeacons/QR/NFC are not interesting in terms of providing information "on the spot", let alone advertisement. OK, then maybe microlocation? Finding lost items? Checkin/checkout? Payments? I don't know, none of these is so unique and indispensable that it triggers the excitement light bulb in me. Most of these things can be achieved somehow else, except maybe finding items lost within 20-30m from where you are.
Maybe the problem is that iBeacons are a bit too passive/static. But even a full BLE device that can transmit a bit more complex information is still debatble in terms of value. Where are the BLE A/V remotes, why aren't they replacing the IR ones? Would you trust a BLE baby monitor? How important is BLE for fitness tracker users? (Answer: somewhat, but if BLE never existed everyone would just use the USB connection to charge and exchange information at the same time, no big loss).
Plus purely engineering problems, such as unreliability, poor battery life, etc.
So let me be that guy who turns out to be wrong some years from now, but: despite the hype BLE turns out to be a niche technology with poor capabilities and questionable benefits.