Crucible rewards pretty good amount of loot faster depending on which mode it is. Which means even quicker leveling/farming materials for some. I try to avoid Crucible as I am terrible, unless there is an event: Iron Banner for the pain and armor with actual good stats now, Heavy Metal for lulz, and Arms Week due to Combat Telemetry is faster to acquire in larger quantities. All three of those also seem to boost the loot drop amount even more than normal Crucible, therefore should pull in more players in during their weeks. In contrast to Competitive and Trails players who tend to have a larger incentive to play PvP over the regular player population during non-events due to the armor and weapons they aim for.