There are much better business arguments to make here then "oh no! The 3 trillion dollar company might have slightly more overhead managing text messaging!"
From a business perspective, I'm much more sympathetic to arguments that iMessage is a perk Apple wants to keep as incentive for more users to switch to Apple's ecosystem and, likely more important, lack of cross-platform interoperability raises the cost for existing Apple users to transition to Android.
Are you claiming Apple would have to pay fixed costs a second time because new users were added to the already existing service?
And are you claiming that 1 million dollars is a lot of money to Apple, a company worth over three million million dollars?
I was responding to someone who said the extra overhead for running a chat service that has more people use it would be notable for Apple. A business argument - not a legal one.