There are 2 things I just don't understand with some of the comments here:

1) If I'm doing it whilst waiting for the duty finder, surely you have to check on a semi regular basis which allows you to move or jump?
2) If I'm doing nothing at all, what possible benefit do I get from being logged in?

I really am struggling to see an instance where I personally would be away from my keyboard for 30 minutes if I was playing. I don't see a negatitve to it other than maybe having to relog in. I would say thats a minor annoyance rather than a major issue.

On the positive side, this helps:

1) People that want to play now log in
2) Improve server stability/lag

I've yet to see a cohesive arguement of why the negatives outway the positives for the collective group as of yet. It seems that all the negatives are very specific to specific individuals.