The difference is that my device isn't incompatible, Apple just doesn't want me to run iMessage on it. They don't just not care, they're actively blocking companies that released clients.
There’s iMessage the app and then there’s the proprietary Apple Push Notification Service. that Apple use in its implementation.
The iMessage app is incompatible with non Apple devices - there is no iMessage app available period outside of those that run on Apple operating systems.
The APN is not licensed for “public” third party usage unless permission is explicitly and expressly granted by Apple.
So yes, your non Apple device is 100% incompatible with iMessage, and unauthorized usage of the underlying APNs is illegal under the Apple Terms of Service.
