So dramatism is ham actors playing through arty nonsense, gamism is munchkins who want to beat the GM, and simulationism is rules-lawyers who argue over ballistics?
No, those are rabid stereotypes. Even if the stereotypes have some truth to them, the Threefold is not about just the lowest common denominator. There are good and bad examples of each type of game. A pure dramatist might run a gritty, low-key drama where the PCs are true-to-life characters who perhaps concentrate on their work. In this case, the dramatic story might be framed around how they relate to each other and the tension produced. Dramatist campaigns also include comedic campaigns, where the in-game action is tailored for humorous effect rather than classical “drama”. The key is that in-game events are tailored based on how satisfying the storyline of the campaign is. A gamist could run a mystery game where the PCs are challenged to find the killer based not just on physical clues, but also on the personalities and motivations of the suspects. Note that this is similar on the surface to a dramatic story, but the emphasis is on making it solvable yet challenging to the players.