I have chopped at final tables during live play many times. I prefer a 3 or a 5 way chop but that's just me. The reason we have done this is most of us know that the game can get over quickly once you are down to just a few people but more often than not that is not the case. The final few players know the there is a big difference between 3rd, 4th or 5th place money compared to 1st place money and the play can last a very long time at a final table when everyone is focused and has their eyes on the 1st place prize. This shortens the game, makes everyone happy and makes 2nd-5th place finishers end up with more money than they normally would have gotten. And unless there is a HUGE chip difference between the chip leader and others the chip leader is not guaranteed to get the first place money anyways. Bad beats, cold cards, etc; all happen. So I do not see this as collusion but being smart.
I remember one time in particular during a smaller tourney where they only paid out to 4 spots due to only have 43 entrants. I was in last place with the chip count and everyone paused the tourney to discuss a possible chop and possible payout to the bubble (which should have been me). We were down to 5 players and the chip leader had more than double the chips of the 2nd chip lead and refused to speak about a chop or a donation to the bubble. He was a tourist and the other players and I were all regulars who knew each other. I was irriatated but the other players (all men) were downright pissed at this guys attitude (he was pretty rude about the whole thing). So the 3 of them became quite aggressive against the chip leader (he really was being an a@@) and instead of me going out in the bubble the chip leader went out in the bubble! We all laughed so frigging hard! Served him right too! And if he had just agreed to pay the bubble he would have made his entry fee of $140 back plus a small profit (enough to cover gas and a drink). They even offered to just pay the bubble and wait to get to 3 people to discuss a chop again he was such a jerk about it! Ahhhh, I love the irony of what happened to that guy!
*Anyways, just a little story explaining how a chop would have worked in the favor of the chip leader.