The difference is that for iBeacon to track devices the user has to download an app related to the beacons and give permission. MAC address tracking happens without the user giving consent.
I'm working at a place that uses a simple app running on a Raspberry Pi to update a dashboard whenever a known Bluetooth MAC comes into the building, with no need to turn on discoverability or pair with the Pi.
Not on the iPhones and Android phones of the people whose names are consistently correctly displayed on the dashboard. The MAC address had to be entered into the dashboard software manually, but no interaction was required on the phone whatsoever.