[arijun]

If they’re not done loading the plane, they don’t have to make an announcement about it because it’s self evident, whereas if everyone is sitting down and ready to go, they will let everyone know what the holdup is.

Just yesterday I took a flight where they asked everyone to try to hurry up loading so they could get the plane off the ground sooner.

[naberhausj]

I've also been on flights where they asked us to hurry, and then we (flight attendants included) sat and waited for other things to be completed. Not saying that was what you experienced, of course! Nor am I complaining. My understanding is that gate attendants get penalized if they're the reason the plane is held up, so I understand why they'd play it safe and hurry people.

I'd love to see some hard data on this (I've tried to find it in the past, but there's so much fluff about this subject)!