It might be hard for such change to come since it’s been this way for a long time. The difficulty also arises in how would they make such quests so that they are fun and not so repetitive, and that something people would enjoy. That means that they have to invest a lot of time and effort to create this system of having daily quests ( story, rewards, objectives ).
I like the daily achievements because they are general. They have connection with about anything you do and you don’t have to go out specifically to hunt it out so you can do whatever your doing and be doing the daily achievement at the same time. Having a daily quest that might reveal some things that the player hadn’t known before or hadn’t had a chance to do might help bring more interest to the game.
Good suggestion though, never thought about it.