Actually, I would say the reason there's no queen of elven peoples now is because there isn't an elven culture now, and the immortal elves can't 'come out' about it without going into a whole lot of stuff about the Fourth World, among other things. As for why the two Tirs are so different, I'd have to go with more than just 'competing for the soul of elvenkind'.
Tir Nan Og plays HEAVILY off the old Irish legends of the Sidhe and the Faerie lands. As such, it is steeped in mysticism and an 'Old World' flavor. Plus, being an island, it is relatively easy to seal off unwanted cultural influences if you want to.
Tir Tairngir, on the other hand, is in Oregon. They don't have that same kind of heritage to play off of, so they made it less of a fairy tale, and more of a mystique, which, for all its fantasy flair, has been done more than once since the middle ages. Those paladins in the flashy plate armor with the gleaming swords. The magical firepower they displayed when they seceeded. Having a dragon on their ruling council. Military parades. The Right of Challenge. All of these things are bread and circuses. It is the best way for a regime surrounded by other nations with vastly different cultures to maintain an identity and keep a tight control on their people at the same time.
