> "I’d like for Signal to reach billions of users. I know what it takes to do that. I did that," says Acton. "I’d love to have it happen in the next five years or less."
When you look at a platform like Slack, it's fine for the devs to say that they don't care about certain users, because Slack is not a universal chat app. Slack has a very specific market: business users. Other users are nice, but not really required, and it's fine for them to go use something else. Signal on the other hand doesn't really have a specific market; they've always described their target market as just 'everyone'.
This is extra-tricky for a chat app because network effects come into play. An app that I can use by myself without relying on anyone else doesn't need to be particularly inclusive: 90% support (or even lower) is probably good enough. But if Signal decides that it's not for 10% (or even 1%) of the people in my social group, then there's a very real chance we might all abandon it. Supporting 99% is excluding not just 1% of your users, but also everyone directly connected to those 1% of users.
And honestly, I would push back on the idea that smartphones are going to reach even 99% saturation any time soon. There's an very consistent demographic of people who don't have phones: kids who are given hand-me-down tablets or laptops. I know a nontrivial number of parents who are waiting longer to give their kids phone numbers, but they still want their kids to be able to message friends and family members. I don't think in 5 years we'll be at the point where every single 5-10 year old has a smartphone.
This is exactly the situation I'm in, where I'm trying to figure out how to allow younger family members to communicate with me, with their parents, with their friends. Even if I set them up with phone numbers, I'm asking them to break contact with anyone else in their social network that doesn't have a phone.
And as the OP states, it isn't just the people who avoid mobile phones who won't switch to tethered protocols, but people who want to message the people who avoid mobile phones. And a high proportion of us have elderly relatives, and we email or Skype or Facebook them.
> “It’s not designed for you” is a reasonable response to you’re building a niche product for a niche audience. But it’s important to note, that is explicitly not Signal’s goal. Signal is advertising itself as an encryption platform for everyone.
Aren’t people with no phone increasingly niche?
I’m not trying to be combative but I would argue attempting to build your app for every single use case is literally a million niches which would require so many concessions and that is the opposite of Signal’s approach. Signal has no interest in building for odd and strange use cases and instead choose the most likely use case and build specifically and securely for that use case.