LFS has become more popular (which in a way is a shame, as more and more of the newbies are NFS junkies, or ricer wannabes), and so there are more people in the demo servers (and in S2, but we're talking demo, so I'll stick with demo comparisons).
Now, lets say that 10% of people (in demo mode) are ill-mannered, bad-driving noobs/wreckers. If you have ten times the total people, you have ten times the noobs/wreckers. Simple. The ratio hasn't increased, although the probability of getting lots on a server has increased.
But then, the standards in demo land are well known, and any 'complaints' should and do fall on deaf ears.