I'll vote gimmick. I've made pickles from time to time. The outcome is based on simple chemistry. The tried-and-true method was an open crock with a board laid on top to hold down the pickles. I had water valves like that when I made wine. Different process entirely. Air isn't an enemy of making a pickle. Making a pickle is embracing the souring gremlins and air is often the vehicle that carries them to your product. Look at cheeses and all the natural yeast that define specialty cheeses.
The world is too involved in shutting out nature. We have to have soaps that kill 99.8% of the evil stuff and then head off to the doctor for our allergy shots and such. Let your immune system do it work and don't force today's version of right on some poor pickle.