The HQ is only double instead of triple exp over the NQ, but the NQ has been doubled for all leves (single or triple turn in).

This means your HQ turn in is worth 33% more than it was before the patch.

They never said the reason, but I'm sure it's because of the people leveling their crafts without crafting. Now you'll get about as much exp from making it yourself and turning in some NQ and some HQ as you would from handing someone else the stuff and having them do it for you.