Let's say there's a train. It's a lightrail, or a subway, or some other rapid mass transit line that conveys people around a metropolitan area.
The train line starts out in the suburbs. In the 80s, numerous office parks were built out there, and later that office space emptied out and was filled up again by (let's say) tech startups. Now your metropolitan area has a growing startup industry, which means that after the train makes its first few stops, it's beginning to get quite full. Most of the people it picks up are young white men, because this city is in America and those people constitute most of the tech workforce. Because the train is empty when it begins its journey, they are almost always able to find a seat, and they sit.
The train makes a few more suburban stops and a handful of people filter on. By this point, they are generally unable to find seats. It's ok. At the next stop they'll hit the areas where people with good jobs in the tech industry can afford to live, and the young men in the seats will begin to slowly filter off.
At the next stop, though, the train also begins to pick up people making the reverse journey: those who work in town and whose commute home begins in the city proper and will end an hour or two hours later in residential suburbs where housing is cheap. Let's say a disproportionate number of these workers are young women. They are coming home from more traditional offices with strict dress codes, which you can tell because suddenly the train is filling up with people in high heels.
At this point there are almost never any seats on the train during peak commuting times. The seats are filled with the tech works picked up outside of town, who quietly read their kindles, or listen to their music, staring blankly into nothing. They may or may not notice that the aisles in front of them have crowded with young women teetering in high heels as the train turns, brakes suddenly, and jumps forward again.
But the tech workers are slowly reaching their various destinations. The train goes much more slowly now, as the densely packed train lines are shared by multiple routes, and other trains on the same route. The stops through the city where the tech workers get off are the slowest part of the journey.
When the tech workers do stand to leave the train, they leave vacant seats. Usually these are nabbed by someone not wearing high heels who can reach the seat more quickly. Sometimes a tech worker will use the vacant seat to put his laptop bag down so it doesn't get stepped on by all the people standing.
People on the train are beginning to notice a problem. Women are constantly falling on people sitting in the seats. Sometimes their shoes or their laptop bags do indeed get stepped on. It's a quandary for the tech workers sitting in the seats because most of the people falling over are women in high heels and most of them are men, and it's happened more than once that someone has fallen and someone has tried to prop them up and inadvertently grabbed their butt or something.
So the tech workers get together and decide to do something about it. They are good guys and they want women to feel safe riding the train without feeling like their only options are to fall over or to get their asses grabbed. One of the women tech workers points out that maybe the women would feel safer if the tech workers wore catcher's mitts, so their helping hands were more like a comfortable guard rail than a lecherous threat (though she is speculating because being a tech worker, she doesn't have to wear high heels to work). The men tech workers figure this is a solid suggestion. They all begin wearing catcher's mitts.
It works. The women are much safer. They still end up with bruises or even scrapes sometimes during their commutes home, but they can rest assured there are people they can fall into who won't grab their butts.
Frustratingly, though, the women continue to fall over. Shoes and even laptop bags still get stepped on. It's hard to read your kindle while wearing catcher's mitts. The tech workers feel annoyed that they've organized to do something as a community to make the train ride better and their good intentions seem wasted.
No one knows how the women in high heels feel. It's impossible to have a conversation with them while they're standing way up there.
A woman tech worker points out that if the women in high heels had seats, they wouldn't fall over or get their asses grabbed. One of her male colleagues helpfully explains that if the men tech workers gave up their seats, there would be no one to catch the women in high heels.