As with many things travel, insurance is a matter of choice. Travel Health Insurance seems to be a lot more expensive in the US than elsewhere. Policies in the US usually include trip cancellation and medical coverage and often run 5-6% the cost of a trip.
Given the amount you travel, Mac, the investment of a few hundred dollars a year seems prudent to me. But when I was 30 the thought of insurance never crossed my mind. Not once.
A few years ago I did start buying trip cancellation (and health) insurance because our parents were becoming elderly. As fate would have it, two days before we were to leave for Central Europe my mother-in-law fell and broke her hip; my wife had to stay and help her out, so we had to cancel the trip. We were refunded the $5000.00 that trip cost from the insurance company, no hassle or questions asked (after documentation was provided). So I've seen the value of insurance firsthand.
But PortMoresby is right, insurance is not for everyone and each person needs to decide how much risk he's willing to take. I'm very much for people having the right to decide for themselves (and, of course, living with the consequences of their decision).