Hi, littlebrightp. This appears to be a far more widespread problem than it may originally have appeared. People on the official forums are oftentimes not reporting it because they're making the assumption, given what they've experienced after (in some cases) completing the entire game, that there simply is not practically any "banter" in Dragon Age: Inquisition at all. This is (thankfully) quite erroneous, as I have discovered via written accounts of copious volumes of companion banter whilst other players have explored the field, as well as user-uploaded gameplay videos expressly detailing all those myriad encounters which many fans such as myself are missing out on entirely.
This is the thread I started on BioWare's forums this morning:
http://forum.bioware.com/topic/525267-as-suggested-posting-this-topic-here-many-players-are-reporting-a-bug-in-which-party-banter-is-incredibly-rare-no-matter-who-we-bring-along/
Note the number of people not only to have confirmed they're having this issue but also to have stated that they didn't know what they were missing out on and were prepared to deem the lack of banter a flaw of the game as opposed to its misfired coding. Ultimately I am certainly glad to hear that some players are wandering around with chatty companions, but nothing on my end has changed the fact that in 51 hours, spanning all party members across at least six regions of the game's world, I've had perhaps six or seven instances of party members conversing with one-another. The same can be said for many other players, although some have reported the scripting error "seemingly fixing itself" eventually. None such luck here. The bug appears to span multiple platforms.
A quick recap for BioWare employees: "party banter" -- AKA companions conversing with one-another in the field -- is exceptionally rare for an apparently-considerable number of players across all platforms, regardless of where we are, what we're doing, how far into the game we are, who we're with, or any other quickly discernible variable. This is confirmed not to be our personal objective opinions on how much is "a lot" because we have seen videos of other players whose levels of party interaction have been magnitudes far, far greater than what we've experienced.
I have decided to halt my progress on what is otherwise a fantastic game because this element of the Dragon Age series is a personal favorite of mine. I play BioWare's games (and indeed, most games I dabble in at large) for the rich storytelling that is made possible by talented authors coming together to weave exceptional stories into terrific characters. This bug disallows me from hearing much of that content and is essentially a game-breaker for me until it's resolved.
Thanks for your consideration and congratulations on a stellar Dragon Age: Inquisition.