I'm generally against the In Medias Res style of storytelling for an RPG.
I think it's important for the player to have a brief period before everything falls apart to get a sense of their character, which helps in figuring out how that character responds to crisis. The Origins provided this (Regardless of other failings) and it was something I found lacking in the last two games. I wanted a Conclave section that would expand upon the situation and my character's motivation. I wanted a Lothering section for Hawke.
I disagree. I think In Medias Res is the best way to start off an RPG. Bioware's problem isn't using the method at all - it's that they completely suck at using it. When well-done - and I think the best example this year is SW Force Awakens - you can have a powerful and dramatic moment that introduces the premise of the setting and gets the player involved and committed to the action.
The problem is that Bioware loves introducing absolutely nothing of consequence to their narrative in the opening.
I don't think it's possible to get a sense of your character before you're exposed to the setting and the plot. DA:O needs you to be a Grey Warden wholly dedicated to saving Ferelden by being in it. The Origins not only don't give you this motivation, but give you a plethora of reasons to have every motivation but the most central one to make the plot work.
The most essential part of DA:O is that - notwithstanding Duncan dying and Ostagar - you identify with your role as Grey Warden, you actively want to continue in it, and you will publicly announce yourself as such. But your Origin ties you to a very different narrative and conflict and gives you every reason to want to dessert, and you never have a chance to connect to the role or mission of the GWs.
DA:O is a complete failure when it comes to actually establishing the rules of the game.