Currently (and often throughout the course of this game), dungeon XP is not just bad, but LOLbad. Fact is joining a group to run a dungeon is a huge negative XP proposition, given the enormous amount of XP you just lost while running it. The exception to this is the single time you run the dungeon for the first time - yes, a one-time occurrence. Or if it's the daily - a one-time daily occurrence.
Someone need a tank or heals to help with a dungeon? Yeah, it's gonna COST you time and XP to help them.
For chrissakes, ESO is an MMO, and the group dungeons you've made are a ton of fun and well-done. Why discourage people from grouping up and enjoying them? Especially those of us bored silly with repeating the same quests on alts?
Group finder is a joke due to under-use: people find standing around major cities spamming for groupage a more efficient use of time (so much fun!). Please fix your incentives and priorities.
SUCH AS: encourage players to join group dungeons YES! Encourage players to run chicken circles spamming aoe's in undead areas NO! At the moment, it's the reverse. Fun game that.
There is wonderful content in this game: please encourage players to enjoy it.