All these people getting upset about the lack of iron sights makes me realize they've probably never played an FPS without it. They don't know how drastically it changed the flow of combat and the general feel of the game. Which makes me feel really old.
Consequently it also makes the reasoning behind adding ADS to Halo 5 more evident. I can't believe people are actually arguing ADS is an advancement in game design. Clearly those are the people who are giving feedback that informs the development of Halo. Please go play Quake live, Battlefront 2 or Halo 2 and see that ADS is a feature that gas a profound impact on the way combat plays out and that games can be a blast to play without it.
Or it's just a preference. I like ADS in some games, others I don't. Some of the arguments like with Battlefield against ADS are really due to map size, flow, and concentration rather than the mechanic itself. Hell, there's some games like Titanfall where, while ADS is present and useful, I prefer firing from the hip due to the other mechanics of the game.
With how this Battlefront is looking to be designed, not having ADS was probably the smart way to go. I also doubt most people will give a shit so long as the shooting itself is good. But that doesn't mean ADS can never have a place in a SW title or that the mechanic is awful.
Edit: Aim assistance better be incredibly light. Without ADS it shouldn't be as much of an issue, but it's something that Destiny made me despise in multiplayer as it makes it difficult to deal with multiple people effectively.