No, what they are saying is that by increasing margin requirements they reduce the need for their computerized systems to close trader positions. Each margin call probably costs time and money to process. Even if its computerized you still get confused traders calling up and asking what happened.
I don't know about other firms but Transact Futures has a daily loss limit. You exceed that limit and your positions are automatically covered, and you are locked out of making any more trades that day.
Kinda hard to close a position when a trading limit or a NYSE trading halt is hit.... We'd move in a flash to a broker who can do that.
maybe a little late to comment; for the record my margin requirement during to day is now basically equal to overnight. for me it made no difference since i carry future option positions 24/7, so i always base my trading on overnight margin requirements. before the change, i had almost double the free margin.