Some additional thoughts on the concerns that have been raised in this and other threads, loosely paraphrased:
Don't you understand that no one likes missions? Why are you keeping any piece of the system?
We understand that many players are unhappy with garrisons, and in particular with the prominence of follower missions in Warlords of Draenor. We're certainly not sitting around, saying to ourselves, "Wow, everyone loves managing followers and doing missions; let's just copy/paste this feature into our next expansion for an easy win!"
We agree that, especially in the long run, the balance of content and rewards between garrison missions and core world content was a big problem in Draenor. Players too often found themselves without much reason to bother with dungeons or outdoor content, possibly logging on to raid or PvP, and otherwise just checking in to collect mission rewards and send followers out on new ones. And after a little while of that, it's awfully easy for it to stop feeling like a proper MMO experience.
We've tried to tackle this problem throughout our design of Legion. We've focused on replayable and varied outdoor world content and dungeon content as the heart and soul of the Legion endgame, and on reward systems that will support the continued relevance of those systems.
But at the same time, there are people who do enjoy the mission minigame, and there are some positive elements, such as a bit of offline progression, and the fun of looking forward to a reward waiting for you when you get home and log in. Not all aspects of the game are intended to appeal to all players - that's part of the challenge of creating a single game that is played by such a diverse audience with different preferences and playstyles. But while garrison followers and missions were a substantial portion of the content in Warlords, Order Hall missions are probably more like 3% of Legion.
I understand that there is a fair amount of cynicism, and there are some who are probably reading this right now and thinking that it's just a bunch of nice-sounding words trying to cover up our sinister plan of mission-table supremacy. But even if we wanted to, we know that we can’t hide anything here. Well before Legion is in anyone's hands, people will be experiencing the system in its entirety in beta, and we'll be judged on that basis.
But there's key player power at the bottom of my Order Hall tech tree, so isn't that gated behind missions?
Actually, no. As I mentioned in my post in the Alpha forums, what players are seeing in Alpha right now lacks context, admittedly because we haven't provided much. The research you can initiate in your Order Hall to unlock various perks, culminating in a strong player-power reward, requires Order Resources. Order Resources are not in any way gained through missions. You gain Order Resources from quest content: from the one-time Order Campaign quest arc, from treasures around the world, and at max level from outdoor world quests. If anything, missions are more likely to serve as an outlet for excess Resources once you have your research needs covered.
The Order Hall campaign immediately has you do missions that take a day to complete. That sounds terrible.
That's good feedback, and definitely the sort of thing we may adjust. Let me try to explain the intent here: The core of the class Order campaigns is epic quest content that is custom to your class. If you're a Death Knight, you might be working to raise a new set of Four Horsemen who are powerful enough to stand against the Legion; as a Mage, you may be investigating a plot that threatens to undo Dalaran from within; and so forth. That's what the Order campaigns are. We start you on these chains during the level-up experience, but they're intended to be a story that unfolds over time, complementing the game's level-up and endgame progression.
In Warlords, when we had the Garrison campaign quests, we presented a new one each week, but there was no real indication where the next step would come from, or how long you would have to wait in order to continue. This time around, we want to avoid having gaps where there's no quest in your log. Having occasional steps where we ask you to run a few missions with long completion times seemed like a more elegant way to do that, allowing us to weave in a bit of storytelling, as opposed to just "hey, come back next week for the next step."
I understand that most of the discussion is based on bits of information that emerge from the Alpha, and I know that it's difficult to truly reassure you when you haven't yet seen the things I'm talking about firsthand. But hopefully trying to share our goals and philosophies, as well as acknowledging past missteps (we hear you - really!), can provide some guidance about where this system is going to end up when it's complete.