Personally, my greatest source of frustration was that the release was falsely labeled as "Early Access."
For all the multiple Early Access projects I've participated in (even before early access existed, for that matter), this almost always meant at least some degree of back and forth between developers and participants. You know... actual honest-to-Bob "participation."
Bannerlord, whether it was the intention or not, ended up as "financing/pre-order" release (something Steam EA guidelines make clear it shouldn't be). Hell, even the "feedback and suggestion" forum was tossed away to "community moderators" so that Taleworlds doesn't have to bother reading, much less replying. At all.
What frustrates me is that, after being teased all the "improved" features, most of them were back-tracked on (such as castle construction or settlement upgrade to another type). After all the dev blog posts hype about Bannerlord being such an improvement over Warband (and, admittedly, the graphical improvements are there), we end up with decisions like the dumbified "village is no longer independent fief" that impacts too damn many elements for my liking. A lot of the "improvements" are side-steps, if not outright steps back, and then Callum comes out with this gem of a "action game with just some strategy elements sprinkled around."
So we have no meaningful input into design direction (because good luck figuring out what ideas TW is looking for, if at all, with not a single official post on even the Feedback sub-board), the design decisions that you CAN see in the game are all over the place (and mostly existing in disjunction of other elements), the "priority list" is just polishing stage, there is no indication Taleworlds even considers attempting adding more than a "sprinkle" of strategic elements (you know, the key major improvement of any larger mod in Warband, so apparently their customer base was rather interested in improvements in that area), and I won't even mention the complete lack of any non-PR communication (aside from occasional posts from Duh or Mexxico buried in some threads, so basically only accessible to somebody living on these boards religiously).
I am perfectly fine with missing content (I "played" plenty of EA projects that started from tech demo stage) - as long as there's meaningful show of progress. Not really something that applies to Bannerlord, considering we're near 4 months since the horrible first release (the amount of easily fixable issues it had made it clear they didn't even bother attempting to polish it up before tossing it out with the hefty price tag), and there has been next to no progress on actual content.
I mean, seriously, they hype up adding a sodding "Create Kingdom" button in the "EA Update we did so much!" post.
I don't mind bugs, if they are addressed in reasonably quick way, either. At least here TW's record isn't that bad, but EA is supposed to ba a wee bit more than just bug fixing, especially when you release a PlaceholderLord.
What I do mind, is that this is not Early Access in the slightest, at least by the metrics based on my personal experience (for the record, I have credit mentions in several past EA titles, because that's how much I enjoy the process and how much I have participated in several of the projects). And that frustrates me the most, because this was not what I paid a significant price tag to be a part of, and it's not what was advertised, either.
They took the money, and don't even have the courtesy to adhere to even base expectations of what Early Access should require from them in turn. Spoiler alert: taking money and ignoring communication ain't it.
Even dismissing their complete absence from Steam boards (something I think is extremely unprofessional, considering that's their bloody release platform of own choice), the lack of any presence on even the "official" boards actually directing the communal efforts of both feedback and idea suggestions was a huge source frustration to me, until I realized there's no point anymore.
I gave up on this game. It'll end up what it'll end up (and I strongly suspect a lot of people will end up disappointed). "Mods will fix it" to whatever degree they will. Maybe I'll be still around to play it, though considering the pace of Taleworlds' work that's highly questionable. Either way, I know what my response will be from now on anytime somebody mentions this studio and their products.
"Fool me once" and all, and at this point I'm completely disinterested in any excuses as to why this project has been handled the way it has.