Which TSR 2E adventures/campaigns would you point to as being particularly bad here? I can't off-hand think of any. I can think of some 3E one I personally think were (but wouldn't want to get into an argument over it lol!). I can also think of settings getting changed to account for bad novels a lot, but that's kind of different (primarily FR and Dark Sun).
I've seen people criticize Freedom, the first published Dark Sun adventure for this. I don't really agree with the criticism, but I can see where they're coming from.
The adventure takes place at mostly the same time as the novel The Verdant Passage, and has the players being enslaved due to flimsy pretexts to work on the ziggurat being built by Tyr's sorcerer-king Kalak. The adventure is kind of a multi-track railroad: depending on how each PC was enslaved, the PCs will be put in different situations and interact with various NPCs.
The adventure recommends using different scenarios for different character types – e.g. recommending using the scenario that puts the PC in touch with the Veiled Alliance if playing a preserver (wizard), or the one that gets you an in with the templars if you're more morally flexible, and so on.
Meanwhile, the novel in question is about a group consisting of two gladiator slaves, a preserver, and a nobleman templar learning that the ziggurat is a key component in a ritual Kalak is planning to ascend to becoming a full dragon, which in Dark Sun is an extremely powerful creature with 30th level wizard casting and 30th level psionic use (secretly, all the sorcerer-monarchs are 21st to 24th level defilers/psionicists working their way toward dragonhood, but Kalak wanted to take a shortcut) and going on a quest to find a thingamajig to stop him. The book's finale takes place after the ziggurat is completed, and the completion is celebrated by massive gladiatorial games. The group uses the games to attack Kalak, who initiates the ritual and starts draining the life energy from every inhabitant of the city. Being the heroes they are, they manage to interrupt the ritual, and kill Kalak, after which they pronounce the former chief templar (who helped them) the new king, with his first act or rulership being the abolishment of slavery in Tyr.
The climax of the adventure takes place at the same gladiatorial games. The PCs are doing various stuff on the sidelines, or taking part in the "warm-up" gladiatorial matches... until the attack on Kalak. This sets off a whole lot of chaos in the arena, and the PCs have to try to get out while ideally also rescuing others, all while having their life energy drained by Kalak's foul ritual. As they manage to get out, the announcement is made that the King is dead, long live the King, and that slavery is ended.
Some would argue that this is a bunch of NPCs taking center stage and doing the important stuff while the PCs are sidelined, but I disagree. I see this as more of a disaster movie situation. It's not about fighting the source of the problem, it's about surviving it and helping others survive. In light of that, the PCs are doing level-appropriate heroics, and ones that will get them noticed by higher-ups.