Partly the fault of the broken matchmaking and no monitoring on hosts.
Take note of who the host is and keep an eye on their connection. In game after game I see the host suddenly get a red connection (or commonly it cycles red/amber/green. Then you get the "insert host name here" is unstoppable or godlike message and people suddenly start to lose connection.
That and hosts that unplug their internet connection at the end of the match because they lost.