Engine braking is good........engine breaking is bad!!!!!
I say ?Que no los dos?(why not both) Taco shell commercials...anyway... These bikes do have a slipper clutch for a reason, to prevent lock-up. Now this should not be a reason to drop down from 8 or 9k and test the slipper every time we want to slow down.
Indeed, yes we could use the brakes for every speed correction requiring deceleration. We could also buy brake pads by case as well as clean the ever living sh*t out of our bikes from the brake dust every time we go out.
Now let there be the average, rational person that has the ability to downshift at a reasonable rpm while smoothly applying both brakes in order to stop. Or to possibly use appropriate gearing in such situations as heavy traffic or downhill, where it is quite easy and reliable to shift into a gear that is more natural at attaining your desired speed instead of a constant off/on braking/throttle event.