The data you present here suggests that the problem was roughly of the same severity last year.
There is also the issue of the larger rate of change. The fact that more code gets into mainline is a basic requirement. The tools available today and the processes used today allow this.
If you don't allow the code to get into mainline, people will use bad, unreviewed out-of-tree code. Not to mention all sorts of bugs that will be added by distributions when attempting to integrate all sorts of patches.