I'm quite sure if AC would respect it's own commitment to deliver E and SE tagged bags first, it would solve partially this problem. If they could also improve delivery time in general, or even better, commit to deliver them in X minutes after the planes has arrived, people would give AC a chance and check in their luggages.

Now it's crap shoot. You may get them in 10 minutes after deboarding, and the next time around it would take 40 minutes getting them.

People don't take chance, have thight schedule and proceed accordingly by taking their luggages with them on-board