"A cursory glance around you will show many whose innate immune system has served them well for scores of years"
Nice story. Your immune system has likely served you so well because the vast majority of people in the last 70 years have been vaccinated against things like small pox, measles, polio, diphtheria, whooping cough etc. You've been riding on the coat tails of herd immunity, congratulations. It's a bit amusing that you can't see how the actions of others, past and present, allows you to hold the attitude that you do.
Try travelling back to the 1800's and see how long you live. Life expectancy was about 35-40 years of age. No antibiotics, no vaccines, no modern medicine, no other modern comforts like waste water infrastructure. Let's see how your immune system goes without all of the modern triumphs it currently benefits from.
