Can Someone Explain Party To Me?

Why does every table on Party break up withing 1/2 hour? I play on Paradise all the time and you can still be playing with the same people you started with 5 hours later. At Party 20 minutes on a table and all of a sudden you look up and 2 chairs are empty and then on the next deal the guy in the BB sits out and then the guy next to him does the same and before you know it you’re playing a 3 handed game while everyone is bolting for the exits.

Wouldn’t you want to get into a flow with a certain group of players? Granted, I know some of these people play like crackheads but I’ve never seen anything like this before. Anybody have any possible reasoning on this?