The number of players has dropped off precipitously as the format transitioned from 6-handed to 4-handed play. The pace of the orbits increased significantly, exposing the short stacks to a heavy dose of pressure. The inevitable resulted: everyone started going all in! The short stacks were forced to make strong moves to protect their hands and the big stacks tried their best to wrest chips from their opponents.
The rate of bustouts is likely to slow down over the course of the next few levels as the money bubble approaches.