> Personally I believe that the majority of iMessage users are completely unaware that Apple silently upgrades your communication from SMS to iMessage.
You can call it whatever you want, who ever came up with that idea at Apple should have been given a bonus. It's an absolutely brilliant idea that provides Apple users with a solution better than SMS/MMS completely seamlessly.
Whether you or I feel like it's the right, or even a moral defendable, solution is irrelevant for most other users.
I think the word you are looking for is hijacks.