Really, you just gotta consider it like this... much like it was harder for the asmo to survive after the cataclysm, it's also harder to play.
What I mean is elyos get more world end bosses/drops/some skills are better and/or more useful (1 skill may do xx damage on amso, but it'll do more on Elyos)
Elyos quest wise isn't good... rather boring, the storyline for asmo is much better imo.
Also the map design/layout for asmo is more... "fit", can't really describe but it seems to be better for me
Elyos are for those who want to play the game with ease, Asmo for the people who want a challenge.
And dont forget the fact that asmo's were rushed, while elyos had a longer time in porduction