Because everyone can run the mile.
I'm from Boise, where there's an event called the Main Street Mile. It has several heats of the mile. Different waves include: high school, open, kids chasing an ice cream truck, masters, mascot race, corporate, and a team challenge where fireman, military, etc all have to wear 35 pounds of gear.
The whole event is an absolute blast. All different personalities and skills and intensity levels come together for one big party. Unlike longer road races, everyone can watch everyone else's event. It's obviously not high pressure, but it still has a bigger emphasis on speed, and less of an emphasis on merely surviving. Plus nobody takes 6 hours to finish.
I've seen some similar open track meets where lots of people of all different levels mix come together to race different waves of the mile. If people are going to care about track, a lot more of them have to participate in it. People have to have ownership, an investment, to care about something.
Dude trains and trains, finally breaks six in the mile. He wins, and so does elite track, because everyone who shared in the experience with him understands a little bit more about running, and has that much greater of an appreciation for what the elites can do.