How did Twitter, once the darling of the tech world, fall so far? Why have their numbers stalled out, their growth stagnated? Well, any number of reasons. One that keeps coming up is that people “don’t understand” Twitter. This fails the sniff test for me. Aspects of Twitter can be confusing, but the fundamentals are clear. It’s a place to talk in public—in 140 character bursts, but public none the less.

Facebook, on the other hand, presents itself as a private space. Never mind how porous Facebook is with your data, it appears private, because you rarely have to interact with people you’re more than one degree of connection from. There are your friends, the friends of your friends, and—occasionally—the masses of other people on the platform. If the farmers in Myanmar who love Facebook used Twitter instead, we’d have come across them earlier.

Perhaps a useful metaphor here is that Twitter is the public square, a global agora where people will bump into each other and interact. If you’ve ever been to Union Square in Manhattan, you can get a decent picture of what life is on Twitter. There’s people interacting with their friends in one part, a group of Hare Krishnas having a chant in another. In one corner, a large political protest with chalk drawings on the sidewalk. Elsewhere, peddlers sell their wares. Wandering it through it all, there’s passers by and the occasional homeless person asking for spare change. It can be loud, cacophonous, and overwhelming sometimes. Conflict occurs, but—unlike Twitter—there’s an active moderating presence we call the NYPD.

Facebook, on the other hand, is more like your living room. It’s a place for friends and family. Generally, something is not in your news feed unless you have invited it in, deliberately or otherwise. We follow public figures on Facebook in much the same way we would subscribe to a magazine, or turn on the TV during dinner. I can’t say with certainty that Joshua Topolsky’s claim that “If users get abusive on Facebook, they’re dealt with,” but you certainly hear less about abusers on the platform.

Now, compare this to the new social platforms that have come in the last few years. They all have an element of privacy and closeness that Twitter does not. On Snapchat, privacy is imposed through transience. Messaging apps and private Slack channels are limited only to the people you invite. Instagram is limited by form—images, video, and comments—and can be locked down. Ello and Peach are basically incomprehensible, but that might just me being an old man. Twitter is the only social platform that is public by default.

That might be the biggest problem Twitter has. Do people really want to speak their mind in public? There’s plenty who do, and there’s value in a public agora for the Internet age. Twitter has also been instrumental in exposing police brutality, for coordinating disaster response, and just keeping people up to date. Despite this, not everyone wants a megaphone. We’ve seen what happens to people with megaphones who make mistakes. Let’s not forget the saga of Justine Sacco.

Many people in the tech space have been on Twitter now for nearly a decade. Twitter’s older users are older people, often geeks, and have different expectations of a social platform. Some of us have lived in public online since well before the age of social media. Many people in tech are also, let’s face it, in a position of privilege where living in public often does not bring with the same risks as it does to women and people of color.

When you look at it this way, no wonder Twitter’s growth has stagnated. No wonder people are moving towards more private, locked down online spaces where the demands and the risks are fewer. The “hulking hive mind” Topolsky calls Twitter’s “greatest asset” is a wonderful thing to have. If people can tap into that hive mind without having to contribute to it—or can contribute to it safely and on their terms, people might be more willing to come to Twitter again. Until that happens, Twitter will struggle and lose ground to safer, quieter, private spaces. Why should I hang out in the public square if I’m just going to get yelled at? My living room is much nicer.