"They already have Apple Music, so let us keep iMessage." You really can't see the entitlement in that? Why would a person not be supportive of a better way to communicate with everyone, iOS user or not?
I see entitlement in that user's sentiment, but anecdotal evidence doesn't sway me.
And I don't think iOS users have an issue communicating with everyone. That's why iMessage is popular. You receive all messages - texts and iMessages. That's really all there is to the special sauce. Most users (in the states) use whatever texting app comes with the phone. In the case of iPhones, the native texting app also offers iMessages. It's a pretty seamless experience.
What *I* want is for Google to push through RCS, and the carriers to jump on board. Apple will have no choice but to allow their texting app to play nice with RCS. Once that happens, the preference for iMessage will decrease greatly.