The keyword in the poll is "regularly". Hopefully, respondents don't have infections like pneumonia on a regular basis.
I also agree that age comes into play. Yes, most slashdot participants are younger than me but in my mid-60's, I take two medicines a day for high blood pressure, and two a day for cholesterol control - these are for obvious health. I take one a day for control of allergies; one could argue that qualifies as "convenience" rather than necessity. There is a muscle relaxant that I take at bedtime to ease spinal tension and help me sleep - also as a convenience. I have other prescriptions that I use as needed rather than regularly.
However, the point is that until sometime in my late forties or early fifties, I didn't take any "regularly" and had abstained for most of my life based on lack of need rather than any philosophic statement. I expect that many of the "abstainers" are in the same boat.