To be fair, those automated air pumps require upkeep (e.g. compressors fail after awhile and aren't always super cheap to replace when factoring the cost of the part and labor to fix). So that's what your money was paying for, not the air itself. But, I agree it is a bit ridiculous.

As a side note, I highly recommend those portable air compressors that can plug into your car's aux port. Super convenient in the winter time when your tires' air pressure drops.