The thing is a disconnection can happen to anyone. Let's say you had queued up for something, it's your first time and you get a little excited then bam some minutes in to the duty you get logged out/disconnected. Would you have been thankful if the remaining players in the party waited for you to come back or would you have preferred they just kicked you when they can (thus you'd have to requeue again)?

Usually waiting a few minutes seems like the best thing to do because for all we know the player could return within that time, and well if they don't then you can kick them or leave yourself if really necessary. The system is fair to an extend that disconnects can happen, but also as a player you might need to show a little compassion on your own side as well. Although some players do abuse disconnections sometimes to get a kick and avoid a penalty, but it's rare to happen so don't think everyone does that or anything.