The way I see it, being "always on" is one of the worst things about office work. Always on is a constant distraction from doing good concentrated work. I think off by default is a far better paradigm for remote communication tools.
Teams that love Sidekick need to be always talking as if they're in the same room. To these teams, it's not a distraction but critical for getting their job done.
Worst case the pointies force everyone to have it on all day to keep an ear on things.