I have had so many flats! If I hadn't had a spare tire, I would have been stranded for long periods of time. Even with a spare tire, I was stranded overnight out of state because I wanted the flat fixed before I continued my trip - just so I could still have a spare tire - and a good thing, too, because only hours after I was back on the road, I had another flat.
Road hazard insurance does you no good at all if your flat occurs miles from any human habitation on a lightly traveled road.
The tire inflator kit does no good when the tread peels off your tire or a bubble forms in the sidewall and bursts - both of which have happened to me numerous times.
I will gladly, joyfully pay that extra $22 it costs to have a real spare tire, and $50 for an actual tire rather than one of the "donut" temporary spare tires that have become so common.
I will accept the 0.01% increase in gas usage to have the comfort of a real spare tire rather than a can of faulty spray sealant and a tire pump.
And those run-flat tires?
Noisy, short tread life, and hideously expensive.
I would not have flat-run tires on my car. My bicycle, yes. My car? No.
They haven't driven the remote back roads of Oklahoma, Texas, Colorado, Arkansas, Kansas, Illinois, Kentucky, New Mexico, Arizona, California, Nevada - those are some mighty isolated roads, more than 50 miles (the maximum you can drive on a flat-run tire or a tire filled with that fix-a-flat spray) from the nearest tire repair/replacement place. And if the tire blows out or the tread rips off or a sidewall bubble forms - what then?
I want real tires and a real tire spare, not a spray can and a pump.
They claim having a spare is a convenience not a safety feature.