I think a lot of people just don't trust them, which cuts down even more on ranking opportunities.

Race has a lot to do with ranking effort too. For example, choosing drow rules out Darsylon and Eregion to some extent, and choosing arial rules out silver spirits etc.

That said, I did a few quests within the last week and I notice the exp appears to have been upped considerably since last time I did them.

It occurs to me that perhaps you could make some sort of quest exp modifier, so that people who do lots of quests get more exp from them. Not a lot more, but maybe double or triple?