HN is pretty atypical, though. If you're playing a dwarf or Dalish Elf, it's not at all clear why you should give a damn about Ferelden's politics. A City Elf might very well enjoy watching the whole rotten structure tear itself apart. A mage could go either way, depending on who she identifies with. And whether or not the destruction of the Grey Wardens at Ostagar matters is entirely dependent on the PC identifying with the Wardens. If the PC didn't -- if they were just something he was sentenced to -- then the fact that they got killed isn't all that significant.
HN gives you more reasons to care about Howe and the politics, yes.
Dwarf, Magi or Elf, you still got to know Duncan and Alistair and Cailan and (perhaps not all but most) people had ample reason to personally want vengeance on Loghain.
Regardless of how you felt about the Wardens (lets be clear, most players loved them), Duncan and Cailan show you kindness and give you a helping hand - even if happens to suit them.
And like you said, a Human Noble had even more reason to care.
We can talk about whether EVERYONE identified with the Warden and his/her motivations, but MOST people did.
Personally, while my Inquisitor felt a connection with certain companions later it felt:
- like I wasn't given ample explanation and motivations for my character's actions
- why the hell was he just not interrogated and killed in a medieval world where he was the only suspect for killing what is basically the Pope, instead of taken on a stroll with a high ranking officer.... I mean seriously, start matters, and the start here was just... whaaaa?
- like the Inquisition was started just to go and give you some organization you can call own, I really didn't think Cass/Leliana reasons were explained properly (or that the reason were even enough)
- like Cullen was fan service and just "there"
And this is entirely personal, and I don't expecting theists to agree, but speaking as a science-loving atheist:
- I never identified with the Inquisition, and to be perfectly blunt, I think forcing a player to be a quasi-religiuos icon and leader in a game is bad call by the writters... I'm sure there were other ways to form a non-theist organization and with the "save the world" goal.
Doesn't matter if you keep denying it, people just continue on about religion and it makes (me, personally) just not care about the whole thing.
I didn't see a reason to form a religious organization in the first place, I didn't see a reason to care for it later.
- the name itself, Inquisitor, leaves a bad taste in the mouths of many Europeans, knowing what exactly the Inquisition did here. It just felt wrong every time someone called my character by that title.
...
As an example... I'll refer to the Orlais plot.
It was done wonderfully, with good gameplay, decent introductions, some funny moment, good setting. Except...
I wasn't given reason to care. Whether Celene or Gaspar or anyone else ruled, I really couldn't care less.
I didn't know those people and I wasn't given a chance to get to know them.
It all felt a bit like the Denerim Landmeet, just that you were given a background and motivations and reason to care there...
So yeah. All good and great, except they forgot you don't know those people and you do not care about them.
(assuming one hasn't read the books)