I don't get flats on 99% of my rides, but that doesn't mean I'm going to stop carrying the means to fix one. Off the top of my head, in recent memory I've used a multitool while out to --
-make fit adjustments
-tighten bolts that come loose
-quickly true a wheel after busting a spoke
-fix a broken chain
-swap parts when commuting to/from track
-dig glass and debris out of tires
-lend to other people who needed it for mechanicals
-realign cockpit after crashing