You're kidding/trolling right? Many servers only have 2-3 simultaneous wz's running during peak times. During non-peak, some servers are lucky to get a full wz. On pot5 I see the same people everyday. Often I see the same people in back to back arenas/WZs. Peak hours population may, just may, hit one full fleet with 10 people in the second.
So when someone loads into someone else's disaster, but doesn't want to be forced to eat it...... leaves and is then punished.....resulting in multiple other people doing the same thing: a lot of people would rather face a 10 min penalty and browse the gtn, accomplish some other ingame related task, get a drink, and take a ****, rather than waste their time in a disaster.
So yes, 10 minutes absolutely, hands down, without argument impacts queue times.