Why are people pushing past 4000 points in a single versus event?

Actually you should thank them.  That's right thank them. 

In a recent Event I was in it was impossible to reach progression goals because the league that had the top 10 slots didn't want anyone breaking into the top ten.  So because the totals were low if you tried to reach progression every time you got past 10th position (which you had to do to reach the progression goal) the same 5-6 people would start attacking you day or night.

So at least if the competition is out of reach you can get something out of PvP.