It's not about being a hassle to maintain, it's about users thinking they were sending secure messages when they weren't. The simplest explanation is that Signal is a secure messenger, so the app shouldn't let you send insecure messages. I'm sure it lost them a few users but they're not trying to gain maximum market share like for-profit orgs try to.
@jonah@lemmy.one you're alive! Welcome back, this server needs 4 months worth of maintenance!