Find my iOS device prior to iOS 7:
When set could be turned off, or the account deleted with no login required, so wiping the device was an easy way around it, passcode only stopped thieves from getting into the phone, and restrictions could stop the service from being turned off and the account from being removed, but if the device could still be wiped.
After iOS 7:
To turn off, to remove the account, to wipe the device, or in the event the device is wiped, to re-activate the device, all require logging into the iCloud account the device had the Find my iOS device service enabled for.
What remains unaffected:
Anything that disables the devices ability to call home, such as removing the sim card, turning off the phone, airplane mode, turning off wifi, turning off mobile data, placing the device into a metal box, taking the device out of range of wifi or cellular (where possible) services, and most importantly, turning the device off.
Through Siri and/or Control Center, some of the above has been made easier to access, so long as Siri and/or Control Center have been enabled on the lock screen.
But in the end the average thief with even half a brain will probably just turn the device off until they can get the device wiped. With iOS 7, if the find my device service is enabled, even if the thief manages to wipe the device, they will still need the AppleID to log into when attempting to re-activate the device. And as long as they can not get around that, all they end up with is a brick.
Long story short, this story has been blown way out of proportion.