As always, the EFF does an amazing job of pointing out a major privacy issue, this time with iOS 11's radios not being fully shut off via the switches in control center. The obvious negatives are a misleading UI and battery usage, however there is another issue that I'm surprised this EFF article doesn't touch on: passive location tracking of users using their Bluetooth and Wifi radios.
In the last few years retailers have begun implementing in-store analytics in order to track customers as they enter/exit the store using their smartphones' radios. This technology is essentially the equivilent of a tracking cookie on a website; allowing retailers to see when you've visited the store and _even where you went within the store during your stay_. For the record, I've seen one of these systems in action firsthand – it's like watching the Maurader's Map from Harry Potter.
Retailers aren't the only ones tracking you: there's also the London Underground, Alphabet's LinkNYC (which even has an ACLU statement regarding its privacy issues), and, if you work for a large enterprise, your office network.
The ability to easily disable your Wifi/Bluetooth radios was users' first line of defense against this type of tracking. It's unfortunate Apple chose to jeopardize user privacy by switching to this behavior, as they're otherwise doing a reasonably good job protecting users' privacy. Perhaps with enough outcry from customers they'll offer a way to disable this behavior in a future update.