Elezen are not played as much as they would be because they have strange proportions that push them into the uncanny valley. There's a reason people call them "giraffes", and it's because their necks are too long, their heads are too small, their limbs look bizarrely stretched out... usually elf-types are extremely popular because they're the quintessential fantasy beautiful/handsome race, but it's tough to hit that mark if you're out there looking a little bit like ET. Many are hoping that the viera fill the niche of "tall, beautiful, graceful wood-folk" but with proportions that don't look odd.
People who would have played them if they weren't so alien are probably playing hyur or au ra.