It's purely gatekeeping, just like in a lot of other fields. A lot of people make a lot of money from it, so it's not going anywhere anytime soon, unfortunately. I too don't see why one would need a degree to give me a bottle of pills (dispensed by a robot) and read the label (printed by the same robot). I can read it myself, and I'd prefer if human was optional - this reduces the probability of a screw-up.