While each person has tremendous untapped potential to protect themselves without a Shield, why not take advantage of a natural product that will protect you from unnatural energies? If you had a choice between flying between San Francisco and New York, or walking, most people would use the technology of airplane, instead of taking months to walk! It can be thought of as a modern convenience just the way we think of phones and cars. They make our lives easier.
Another way to think of it is that the Universe provides us with all kinds of tools. We take vitamins, receive health care treatments like massage, use power tools, use a phone – all of which make our lives easier and more pleasant.