I think he is referring to a step motor controller as a "stepper". People love the fact that Prusa uses Trinamic drivers instead of no-name drivers.
I personally don't understand why step motor control is something that needs to be outsourced. Just stick an H-bridge between the microcontroller and the motor and improve the control algorithm with every release.
The typical H bridge has many failure modes and disadvantages which are handled by the controller ICs. Not to mention a lot less CPU overhead for the AVR running the show.
Yeah, you can get some feedback from the controllers easily (and then omit physical endstops).
I am waiting for a 3D printer that uses servo motors, though. So many failed prints come from not knowing where the extruder is. But you can just measure exactly where it is, rather than guessing based on how much current the motor used.
