Reasons for the "Bad DMing" Criticism
Railroading and Lack of Choice: The primary critique is that the fight is unavoidable and the outcome of the dialogue with Ansur does not change the fact that combat will ensue. This lack of alternative solutions (e.g., talking him down with high skill checks, finding a cure for his condition) is often cited as a classic example of "railroading" in a game that otherwise prides itself on player choice, frustrating players who expect more flexibility as they would get with a good human Dungeon Master.
Unfair Mechanics: The fight's mechanics, particularly Ansur's "Stormheart Nova" attack which can TPK (Total Party Kill) the party in one turn, are a frequent source of frustration.
The game advises players to take cover behind the crystal pillars, but many players report that this mechanic is janky or bugged, with characters taking full damage regardless of positioning.
The high damage output and specific requirements for avoiding the nuke can feel arbitrary and unfair, leading some to feel the DM (the game's design) is deliberately trying to kill them without a fair chance, a hallmark of poor DMing.
Forced Narrative: The encounter is central to The Emperor's backstory, revealing that he was Balduran and killed Ansur in self-preservation after Ansur tried to "mercifully" end his illithid life. Some players feel the game forces a specific interpretation of events and character motivations onto the player, rather than allowing them to roleplay their own conclusions about The Emperor's actions.
Expectation Mismatch: The core issue often boils down to the inherent limitations of a computer game running a rigid ruleset versus a flexible tabletop campaign with a live DM who can bend rules and adapt to creative player solutions in real-time. Players used to the organic flexibility of a human-run D&D game find the computer's rigid, scripted encounter frustrating and restrictive.
Ultimately, the Ansur fight serves as a lightning rod for discussions about where Baldur's Gate 3's scripted nature clashes with player expectations of a true, agency-driven D&D experience.