I read messages when they come in because they might be urgent and it does not take very much effort to read a message. Most messages are not urgent, however, and the response (or worse, ensuing real-time conversation) often does require some effort. So if I happen to be engaged in something I'll frequently choose to postpone responding until a more convenient time.
In the past people have taken advantage of this "mainstream" metadata to interrupt me further with increasingly desperate follow-ups and/or to jump to cynical assumptions about their value to me as a person unnecessarily jeopardizing our relationship.
So like GP I turn this functionality off and refuse to use platforms that don't allow it to be disabled. This "feature" is not required for good faith conversations between non-adversarial parties.
Do I crave control over your context? Only insomuch as I refuse to be at the 24/7 beck and call of anyone with a phone. If you want to have a real-time discussion with me you can either have the good fortune to have contacted me at a moment in which I was not otherwise occupied or you can schedule a time with me in advance.
