No need to take this personally. I just said what I heard from the people I know and who complained. The rest did not as most of them use Whatsapp and there is nothing they miss in Signal. So saying "Unless Signal's usability matches what the average user expects, nobody will use it" is a matter of perspective I suppose.

btw It looks like the backup problem is something you should blame Apple for https://github.com/signalapp/Signal-iOS/issues/905. It works flawlessly on Android. As for your Siri issue, I wouldn't say it's something "the average user expects". I don't know anybody doing what you wanted to do there.