Meetings should be 30 minutes by default unless there are circumstances that warrant more time. A lot can be done in 30 minutes. That's one thing I agree with Google people on, but then again, people added so many random meetings on calendars without even asking first.
@timnitGebru I love making my calendar public, with large chunks reserved just for me, and enforced pauses between meetings. People can book with me, but cannot make my week a hell of meetings :-)