Personally, I think the choice to go with a more railroaded and concrete personality for Hawke was the right decision for the story being told in DA2.
Compared to DAO, DA2 was a much more intimate and personal story, and one that wouldn't have worked nearly as well if more player agency was afforded to the character.
Think about it. Sure, Hawke sould have theoretically fled from anywhere in ferelden, but the story pretty much required certain key ingredients to be told. he wasn't magically railroaded in to an ancient order and then given the reins, he was a rising star in a single city with a rigidly defined culture.
DA2's story literally dould not have been told if Hawke was, say, a dalish elf or an orzimmar dwarf. The story hinges completely around hawke believably rising to power through circumstances that are logical for his backstory. Being a commoner from Lothering, having a mage sister, not being dalish, and a lot of other things are integral to the belivability of that story. It played a lot more naturally than any of the transitions for the opening choices in origins to the player being inducted in to the grey wardens.
DA2 had several problems, most famously the excessive map re-use and lack of follower gearing options, that stunted its breadth in a gameplay sense, but in a narrative sense it was a very specific story about one very specific small event with very natural cause and effect to that end.
If anything, compared to DA2's story, The overall plot of DAO was far less natural and belivable. You will always be a grey warden, and you will always be immediately thrust in to a position of command over an organization you know nothing about, with no oversight, despite it being an ancient worldwide society charged with fighting the only known global level threat in the entire world.
The thing is, in DAO you had to make that kind of storytelling conceit in order to facilitate the kind of player agency it provided. Your background as a player choice was sensible because, in the larger scheme of things, it didn't matter at all to the story. It was literally just a series of starter quests before the actual plot started.
Hawke's story in DA2 however is integral to the plot from start to finish. He doesn't do a starter bit and then immediately become someone important and have a story from there. For the first act to work at all he HAS to be a dirt poor refugee, with kirkwall ancestry, and a mage for a sister. Kirkwall ancestry prevents him from having elven heritage. Having a mage sister prevents him from beign a dwarf.
There's so much in the game that revolves around certain particulars of Hawke that the player can't choose that they literally could not have told the story of kirkwall without removing the choices they did. That would be a shame, because for all its troubles, what DA2 did exceptionally well was tell an excellent stroy not only about the protagonist, but about those who accompanied him.
That's the difference between the two that people don't get I think.
DAO was a game about the player, guest starring the companions. DA2 was a game as much about the companions (and the city itself) as it was about the player. When you put that much of a premium on the complexities of how companions interact with the player, you have to place limits for those characters to be interesting.
DAI is headin back to the "primarily about the player being the chosen one and how he saves the world" trope, and it looks like a fantastic game. Hawke absolutely deserves a role, if anything because he's an actual character, wheras the player's blank slate Warden Commander from DOA is simply propped up by headcanon with very little actual substance as a character that would be interesting to interact with as an NPC. DAO is not a story about the Warden Commander. It's a story about Ferelden. Ferelden is the main character, not you.
It would be a bit like playing half life 3 and having Gordon Freeman as an NPC. There would be little point. Gordon Freeman, like the Warden Commander isn't a person as much as he his a series of events. He's not going to have interesting conversations with you because he was specifically designed not to have a personality. His Story arc is on solely defined by circumstance and railroading with very few choices that define him, rather than the world, as a character. Hawke is a different matter. Hawke's entire story is about a much more established an interesting character, and the player has influence on a personality and more important a set of core values that define Hawke rather than the country and world in which he lives.
This is why Hawke is a much more natural choice for heavy NPC inclusion. He's easier to define and write based on previous player choices wheras the Warden Commander wouldn't last past a few paragraphs of dialogue because everything he is is already covered in common public knowledge. He has very little substance as a person outside of being the Hero of Ferelden wheras Hawke has a clearly defined personality as Hawke ouside of his legend as the Champion of Kirkwall. In fact, that was the entire point of DA2, to determine who Hawke was, not what the result of his actions was.
I'd love to see my Warden Commander make a cameo, but I don't think he's capable of carrying as a full fledged NPC. He's just not a very interesting person when tracked my metrics one could judge from simply playing the game rather than supporting decisions with an imagined headcanon, and you can't write branching dialogue and a belivable character around the infinite scope of headcanon.