Can you stop moving the goalposts? There's a ready-to-go open source solution for MacOS [1] that exposes a REST API [2] for interacting with iMessage which allows automation and the sky hasn't fallen like you predicted it would. Professional spammers would no doubt be way ahead in capabilities.
Relying on clients to stop spam would break just about every security design principle so that could never be the primary spam filtering mechanism. Indeed, if you search Github, you'll find evidence of this [3].
Allowing a third party gadget to talk to an iPhone to send messages isn't going to open the floodgates to spam any more than they already are, for what I think are pretty obvious reasons. Anyone who could exploit those integrations can already exploit current APIs with exactly the same limitations.
> In contrast you need to hook into Apple APIs / scripting / sqlite databases on trusted apple hardware in order to automate iMessage.
And that wouldn't change, you would still need to pair a real iPhone to your fake "spammer edition" Pebble, and then your Apple ID and iPhone would quickly get banned. Presumably just like it does now if you abuse [1][2], otherwise that's just bad design.
It's frankly ridiculous that this is even being suggested on a "hacker" forum with nothing but wishy-washy qualifiers about how easy or "hard" it would be.
[1] https://bluebubbles.app/
[2] https://documenter.getpostman.com/view/765844/UV5RnfwM#0d8e0...
[3] https://github.com/ZekeSnider/Jared/issues/65
