I love making new characters in a new and improved CC, then sending them off into a new DA saga. It's an essential DA dynamic. It's what separates DA from games (even Bioware games) that use a set protagonist. I'd rather that not be taken away. DA doesn't need to shed its unique function to be a great game. Every new saga is a new jumble, and it's great that way. Clean slates and all that. Plus there's that feeling like you're a nobody again working your way as an unknown paving their way into the unknown- rather than just being a celebrity making a reappearance.
I agree strongly with everyone who gets disappointed at the idea of starting Lvl1 with the character with which we've just gotten to Lvl27, now starting without any of that uberequipment we'd worked so hard for. Disheartening to me. They could, of course, pull a BG2 arse-pull: we were just "kidnapped," stripped of our gear, and, in a DA4 Inquisitor's case, blasted with an experience-removal magic... But in that case, why not just start a new character instead? You're already at square one again anyway. To those who say, "Yeah, but what about Varric?," I reply, "Exactly." It's just as jarring to see all those real life hours I'd spent with Varric flushed away as it would be with a gutted Inquisitor. They could make a DA4 like NWN1's HotU where it's a high-level adventure, but if we have to nullify all our character development from earlier games, I only want to start a new character.
Plus I have no interest in playing my same Inquisitor(s) all over again in a completely different saga. They will have had their story, just as did my Hawke and my Wardens. Why again with an Inquisitor? It's Dragon Age, not Inquisitor Age or Blight Age or Kirkwall Age. Perfectly fine letting my characters pass fondly on with the game they were created in. I loved playing my HoFs, would even like playing another Warden, but not another Hero of Ferelden Warden. (It's bad enough that we were an instant celebrity in DAI.) It's immersive to me that all my previous characters contributed some pivotal world-historic role that is now just lore as they pass the baton. I specifically want to play a character that can look back on my old dwarf DW rogue and say, "I want to be like that dwarf Inquisitor," and ends up living their own story and paving their own role in history.
The only counterargument in this discussion I can at least empathize with is that there should be a greater number of years pass before our new protagonist shows up. 200yrs is a tad long, particularly when events for DA4 have been setup by the end of DA3 (DLC). And frankly I'd miss seeing the reappearance of old characters, miss appreciating how they'd given Leliana a huge boost to her integrity as a character, for example. The reappearances are yet another iconic DA quirk that makes DA special. But, OK, if things happen right away, it begs the question of why wouldn't the Inquisitor/ Champion/ HoF be involved, yes? In this case though, it's not as if the writers are at an impasse. It's not so difficult to come up with a storyline- not feeling contrived at all- of why the Inquisitor was prevented from getting involved. Perhaps the Inquisitor was forced to call on some nobody who Solas didn't know- or someone with a particular background- or someone who just happened to be at the right place, right time. Or a story like Frodo and Sam happening concurrently with the rest of the Fellowship's efforts. Or perhaps the means to defeating the DA4 antagonist will be beyond the reach or power of the Inquisitor- such as happening in a more geographically remote region of Thedas that "southerners" don't even know about yet (since Thedas isn't fully explored). Or the story could start up after some events that the narrator spells out generally- the Inquisitor and Inner Circle went and did this, then that happened, and now we're here... with a new protagonist. And that type of story would require no BG2 arse-pull of a plot... and no returning Herald protagonist.
As to bringing back characters from earlier DA's, I applaud their handling of the HoF and Hawke in DAI... except for having to CC my Hawke. I just clicked "OK" because it was a bit too metagame recreating my DA2 character. (I wouldn't even be able to reproduce the same morph if I were to try on DA2's CC.) Integrate them as big players only indirectly involved, I say, and just build solid narrative reasons why a new hero is needed- or fated by prophecy or whatever. For instance, how could Kirkwall's Champion or Ferelden's hero win DAI if they didn't have the Herald's green-glowing-hand thingy? There's no insult to the audience in the least, just a new game with a new dynamic requiring a new protagonist. Belaboring the Inquisition plot further is neither required nor appealing.