Why dont people Dragon PQ?

You know what's odd, people seem to do the party quests that give the lesser amount of experience more often.

Pretty sure because is kinda boring (same for hob pq) and the reward is not even good for most people who already have a decent weapon.

People don't PQ just for experience.
Kenta's Goggles and Von Leon Belts are far more useful, for most people, than anything you can get from DRPQ.
Although I must say that my alliance's PQ-enthusiasts group used to do all four (Kenta, Escape, Hob, and DR) every day, for a good long while.