When I started riding again two seasons ago, it took me 2200 miles to have my first issue, a rather spectacular blowout. Granted, it then only took two weeks after that to have my first puncture. I don't consider that to be any sort of high rate of failure.

As far as "having" to carry spares? I don't "have" to. I simply far prefer taking four minutes to fix the problem and be on my way. Much better than to have to call someone to rescue me or walk home. All of my vintage bikes had frame pump mounts, and one had the original under saddle tool bag, telling me that the theory was probably the same even 40 years ago.

I carry a tube, just because I don't want to deal with patching roadside. I'll patch when I get home, as I did with that second issue listed above. Also, because there was no fixing the blowout mentioned above, that tube split a good 3".