Back in the day, the best way to level was to spam dungeons.

Anyone who leveled tank/healer will be 'pushed' to try big pulls. At first they panic etc.. but soon it becomes the norm.
Big pulls are not as bad as people think. They simply need to try it more often to get the feeling of it.

Tanks who level via dungeon spam learn how to use their defensive kit effectively.
Healers learn when to cast heals and when to rely on oGCDs + they learn to when to heal and when to dps.

Sadly, after potd/hoh and recently trust, a lot of people do not get to level by spamming dungeons. So they don't get to experience the standard big pulls.