Larian's vision is a big reason for the feedback being so negative - it's not an interpretation of DnD, it's an adaptation with a lot of things included that might make a great game but do not make a great DnD game.
Take environmental damage - The constant fire damage sapping hit points because fire bolt sets things on fire is entirely Larian ideology - the fire does not set cobblestones on fire. It also got changed to 1d6 instead of 1d10 because it sets on fire, but that is not DnD that is Larian.
I can accept certain things need to change to fit into the game, but ultimately crafting from potatoes and eggplants is a Larian thing, not a DnD thing.
TLDR: Larian has taken DnD, spun it larian-style and has failed to hit overwhelmingly positive.
And there is yet another group of player who would say the following...
"Larian's vision is a big reason for the feedback being so negative - it's not an interpretation of Baldur's Gate, it's an adaptation with a lot of things included that might make a great game but do not make a great Baldur's Gate game."
The amount of "outrage" that the game is too much 5e and not enough BG I & II is on par with the people complaining its not close enough to 5e.
So I ask you who is right how do you solve this problem? If you are like most people you think it should be solved in your favor or the way you want the game to be. You'll never get a consensus. And what if they decided to take the opposite side and made the game less how you want it to be?
Larian is damned if they do and damned if they don't . There are enough D&D 5e "purists" and Baldur's gate I & II "purists" that if either side takes a "hard" stance you are going to do nothing but bitch and complain about how the game isn't X instead of compromising and making the game better by realizing it is NEVER going to be a pure mechanical representation of either 5e rules or represent the pure mechanical style of BG I & II. It is going to be its own thing influenced by both camps.
The harder either camps works at to force the game into their own mutually exclusive positions the more unhappy both camps are going to be. And know this, you will NEVER win, so stop trying. Just try to make the game better and by better I mean be open minded to change. Be willing to express your opinions but also be open to the fact the 5e isn't perfect and "house" rules are part of the D&D experience. Conversely be open to baldur's gate I & II not being perfect and changes to how those games approach thing needs to change as well.