There's a number of reasons why there aren't many Eldar playing currently. Low overall playerbase. Less players playing means less people playing each faction. Steam Summer sale also impacts this. Nerf fatigue is part of it for some Eldar players. They don't want to invest time into playing their Eldar only to see more nerfs come down the line for things which are already (in their eyes at least, and perception is important here - perhaps more important that facts and numbers) balanced against the Eldar. The delay for the Eldar campaign and Elite is part of it as well. I know I, for one, was actually more excited about a fancy shoulderpad than anything else... that's how few cosmetic options Eldar have. Which gets into not only low cosmetic options, but low options total. Lack of overall options amongst the Eldar discourage veteran players from continuing to play. Unbalanced LP costs which allow almost no customization for Eldar contributes to this, as well as simply having few choices to begin with. When you have few choices, and then aren't allowed to make half of them, that is discouraging. Significantly lower survivability discourages new players from starting to play. This causes Eldar to have a significantly higher learning curve, simply because it requires an extremely different playstyle from the other three factions. Most of your skillsets for the game are transferable between LSM, CSM, and Orkz, with a few small (but sometimes significant) changes between them. That's not the case for Eldar.