The people who need it aren’t the type of people who’d read it.

I made it my status message as well and all I got was a complaint passed along from my manager because somebody said that it was too rude and that I should be more gentle with my fellow corporate comrades...

I tried that on slack for a while, it made no difference. I don't think most people read the status message. The medium lends itself to the "Hi" type messages unfortunately, there's not really a way go constrain human nature, other than to not use instant messaging at all (I also tried changing my status to a note telling people to phone me, that didn't work either)