Elves are killed as a tradition and absolutely no humans complain about it. Your companions in DA2 outright say that no court would convict someone for killing an elf. Don't forget how nobles can purge alienages and can rape any elf they want. Heck, even a City Elf Warden who saves Ferelden and becomes bann still faces problems because humans to too racist against elves. How do you expect elves to get anywhere or at least be treated as people without getting involved in politics?
Ok, now that's an argument.
As for what they'll do, I don't particularly care one way or another.
I do, on the other hand, find the notion that every group simply must have a representation even if they're just 0,5% percent of the population to be funny.
Next thing you'll know, the surface dwarves will be demanding an Arl.