Ender, I have come to expect that from quite a few other companies. But I have always been naive enough to believe that ArenaNet was different. ArenaNet have made it clear from the start that, even if their development process is extremely iterative, they don’t reveal anything until they are sure about the functionality that will be made available. In some situations (for example with attributes and traits), when they had reasons to change how they had initially announced the system, they publicly announced and explained that change. So yes, if ArenaNet announces a certain feature, it can generally be seen as a promise that this feature will be in the game as described.
And for all the announcements they made about the functionality I summarized in my post above, they never ever told us that they had changed them until after the release… let alone why. And especially if that ‘new direction’ suddenly goes in against everything they have been hammering on that the game wouldn’t do or be (such as the grinding), then yes, I definitely count that as a broken promise.