What do you mean a lot of player that liked 1.8 goes to hypixel?
I mean, Unscrew them :v 1.8 & 1.9 compatible just makes the game to be played at 1.8 anyway, so, hell, 1.9 ftw, besides, player can changes their version whenever they want :v.
And to add, 1.9 only servers, attracts people who wants to 1.9 .-.