I think what Apple’s afraid of is an app like Facebook tricking/forcing users to sideload in order to bypass privacy protections and get full access to user data. I don’t think they’re at all worried about hobbyists sideloading open source apps.
Everyone likes to say “but would Apple would lose the $100/yr from all those hobbyists.” How many hobbyists do you think are out there right now paying $100/year just to load some apps on their phone? Can’t be more than 1000. Even if it were 10,000 that would represent $1 million/yr in lost revenue for Apple. That’s less than a rounding error on just one quarterly report. They really don’t care about that!
Everyone likes to say “but would Apple would lose the $100/yr from all those hobbyists.” How many hobbyists do you think are out there right now paying $100/year just to load some apps on their phone? Can’t be more than 1000. Even if it were 10,000 that would represent $1 million/yr in lost revenue for Apple. That’s less than a rounding error on just one quarterly report. They really don’t care about that!