Playable Elites are what made playing Halo’s multiplayer so enjoyable for me. Halo Reach especially, being different than people who preferred to play as Spartans with your own abilities. Halo 5 looks excellent but, Elites not being playable again really disappointed me. I’ve been playing Halo since CE and before Halo 2 came out I always wanted wanted to play as them. Now my favorite feature is being removed because of canon. Now everyone is forced to play as Spartans whether they like it or not.
TL;DR
Elites not being playable makes MP linear and boring. Human vs Human conflict is stale.