Maybe it's because their initial advertising campaign, and their original comments, on which the game was first advertised and sold, was the statement that they were making baldur's gate 3, which they would be making in the fifth edition ruleset, which they would be translating into the game, and I quote, "As faithfully as possible".
So, many folks who bought into the game on that premise are rightfully annoyed at how completely disingenuous that statement has shown to be. Funnily enough, it's really hard to find the earliest articles and interviews, where these statements and others of a similar nature were first made, nowadays, and their tune has dramatically changed as well. Many folks are annoyed because they used a premise and an advertisement which they never even intended to honour to draw people in and generate sales.... and are in fact on record elsewhere as admitting that what they really want to do is use the branding, legacy and high-profile nature of D&D and the BG series to pimp Their style of games to a new audience... when that's not what was originally advertised, and not what brought many of the folks here to the game in the first place.
We all know this is a video game, and that the rule-set can benefit from many and various changes and adaptations when transitioning to a video game format - both for pacing and for general quality of life... no-one is denying that at all. In many of my own focus threads, I take special care to point out and note rule deviations and adaptations that are actually very good calls and nice improvements or concessions to video game format where adaptation improves the experience. Those aren't the things that people are making threads about, for the most part.
In regards to rules of DnD this is what Swen Said last month to Gameindustry.biz
'You don't want a game to be complicated, you want it to be very natural and very intuitive and so there's a lot of work being done on the background that we haven't shipped yet, where we're trying to say: what is the best and easiest way for a player discovering this rule so that they intuitively take it into account? This early access is clearly obviously a very important platform for us."
"I think when you'll see what we will release compared to where we started, you'll have this feeling of: holy shit, this is very, very accessible, I don't have to think about it, it just makes sense. And that's exactly the experience you have if you play D&D in real life. If you have a good DM, they're not going to bombard you with 300 pages of rules that you need to learn, they're just going to be: hey, you enter a dungeon and there's a door. What do you do?"
"We want to have that Dungeons & Dragons feeling, not slavishly following every single one rule, but really getting the feeling of playing this tabletop experience but everything is being done for me, this dungeon master is doing everything automatically, I'm just having a good time. It's really about us removing the barriers to entry and shoving it in front of people's noses really so that they just give it a go, and then usually it clicks. Because if you go to the reviews of BG3, of DOS 2, one of the things you really often read is: 'I never thought I was going to enjoy this, but here I am, a hundred hours later!'"